Abstract:
A hand-held apparatus gathers and analyzes test data associated with rotating electric machines, where the test data is indicative of one or more operational characteristics of the mechanical equipment. The apparatus, which is operable to be carried by an operator from one machine to another along a test route, includes a sensor input port for receiving a sensor signal from a sensor, where the sensor signal is indicative of one or more operational characteristics of the rotating electric machines. The apparatus also includes a signal conditioning circuit for receiving the sensor signal, and for conditioning the sensor signal to produce a conditioned signal which is appropriate in format to be digitally processed. A processor, which is coupled to the signal conditioner, receives and processes the conditioned signal according to processing instructions and processing parameters to produce a test spectrum. The processing parameters determine one or more characteristics of the test spectrum. A memory device, which is coupled to the processor, stores a plurality of executable test expert modules, each containing the processing instructions for processing the conditioned signal in a particular way to determine one or more of the operational characteristics of the rotating electric machines. An operator input device is coupled to the processor for receiving input from the operator to select one of the test expert modules to be executed to process the conditioned signal according to the processing instructions contained in the selected module. The apparatus further includes a display device for displaying the test spectrum to the operator. The test expert modules contain processing instructions for determining whether the processing parameters have been set according to a predetermined configuration for a particular test point on the test route, and for processing the conditioned signal in a way dependent upon whether or not the processing parameters have been set according to such a predetermined configuration.

Description:
TECHNICAL FIELD 
     The present invention is generally directed to machine testing. More particularly, the invention is directed to a system for automatically configuring a machine testing device to perform further testing of a machine based upon results of a previous test. 
     BACKGROUND OF THE INVENTION 
     Portable vibration analyzers are used to test machines, such as in manufacturing plants, so that any defects in components of the machines may be detected before the defects lead to catastrophic failure. To perform such testing, these vibration analyzers must generally be set up with operational parameters which determine how the vibration data will be collected and analyzed at each machine. Some of these vibration analyzers are preloaded with particular setup parameters to perform particular types of tests on particular machines. With other analyzers, the test operator must have enough experience to know what values to select for the setup parameters for the analyzer to function properly. In some situations, a test operator may collect test data which makes the operator suspect a problem with the machine under test. In such a situation, the operator may wish to perform a special test to gather more information on the suspected problem. However, setting up the analyzer to do a “nonstandard” test may require the operator to be an expert in machine fault testing requiring the specification of 15-20 parameters that control the test setup. 
     What is needed, therefore, is a machine testing analyzer that automatically determines test setup parameters based on a suspected problem with the machine under test, or based upon a particular portion of a test spectrum designated by the test operator. 
     SUMMARY OF THE INVENTION 
     The foregoing and other needs are met by a hand-held apparatus for gathering and analyzing test data associated with mechanical equipment, where the test data is indicative of one or more operational characteristics of the rotating electric machines. The apparatus, which is operable to be carried by an operator from one machine to another along a test route, includes a sensor input port for receiving a sensor signal from a sensor, where the sensor signal is indicative of one or more operational characteristics of the rotating electric machines. The apparatus also includes a signal conditioning circuit for receiving the sensor signal, and for conditioning the sensor signal to produce a conditioned signal which is appropriate in format to be digitally processed. A processor, which is coupled to the signal conditioner, receives and processes the conditioned signal according to processing instructions and processing parameters to produce a test spectrum. The processing parameters determine one or more characteristics of the test spectrum. A memory device, which is coupled to the processor, stores a plurality of executable test expert modules, each containing the processing instructions for processing the conditioned signal in a particular way to determine one or more of the operational characteristics of the rotating electric machines. An operator input device is coupled to the processor for receiving input from the operator to select one of the test expert modules to be executed to process the conditioned signal according to the processing instructions contained in the selected module. The apparatus further includes a display device for displaying the test spectrum to the operator. 
     In preferred embodiments of the invention, the test expert modules contain processing instructions for determining whether the processing parameters have been set according to a predetermined configuration for a particular test point on the test route, and for processing the conditioned signal in a way dependent upon whether or not the processing parameters have been set according to such a predetermined configuration. 
     The test expert modules have the ability to alter the data collection set-up methods based on the data that has already been collected by the analyzer. The test expert modules, in essence, learn from the collected data. 
     In some preferred embodiments, the test expert modules contain processing instructions for setting a maximum frequency and a resolution of the test spectrum based upon whether the processing parameters have been set according to a predetermined configuration for a particular test point on the test route. One test expert module gives the operator the ability to invoke a Turning Speed Detection test. This test expert module can also be invoked intelligently when the equipment to be monitored is defined as a variable speed machine. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages of the invention will become apparent by reference to the detailed description of preferred embodiments when considered in conjunction with the drawings, which are not to scale, wherein like reference characters designate like or similar elements throughout the several drawings as follows: 
     FIG. 1 depicts a machine testing device according to a preferred embodiment of the invention; 
     FIG. 2 is functional block diagram of the machine testing device according to a preferred embodiment of the invention; 
     FIG. 3 depicts a display screen for selecting an expert analysis module according to a preferred embodiment of the invention; 
     FIG. 4A depicts a display screen showing vibration test data according to a preferred embodiment of the invention; 
     FIG. 4B depicts a display screen showing test setup parameters according to a preferred embodiment of the invention; 
     FIG. 5 is a flow diagram depicting the operation of a High Resolution expert analysis module according to a preferred embodiment of the invention; 
     FIG. 6A depicts a display screen showing vibration test data according to a preferred embodiment of the invention; 
     FIG. 6B depicts a display screen showing test setup parameters according to a preferred embodiment of the invention; 
     FIG. 7 depicts a display screen showing vibration spectral data according to a preferred embodiment of the invention; 
     FIG. 8 depicts a display screen for selecting an expert analysis module according to a preferred embodiment of the invention; 
     FIG. 9 is a flow diagram depicting the operation of a Bearing/Gear PeakVue expert analysis module according to a preferred embodiment of the invention; 
     FIGS. 10,  11 , and  12  depict display screens showing vibration spectral data according to a preferred embodiment of the invention; 
     FIG. 13 depicts a display screen for selecting an expert analysis module according to a preferred embodiment of the invention; 
     FIG. 14 is a flow diagram depicting the operation of an Equipment-Off Bump Test expert analysis module according to a preferred embodiment of the invention; 
     FIGS. 15,  16 , and  17  depict display screens showing vibration spectral data according to a preferred embodiment of the invention; 
     FIG. 18 depicts a display screen for selecting an expert analysis module according to a preferred embodiment of the invention; 
     FIG. 19 is a flow diagram depicting the operation of a Peak Phase Coastdown expert analysis module according to a preferred embodiment of the invention; 
     FIGS. 20,  21 , and  22  depict display screens showing vibration spectral data according to a preferred embodiment of the invention; and 
     FIG. 23 depicts a display screen showing a list of labeled spectral data sets according to a preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Shown in FIG. 1 is a hand-held data collector and analyzer  10  for testing machines, such as in a manufacturing plant. As described in more detail hereinafter, a test operator may use an analyzer, such as the analyzer  10  shown in FIG. 1, to collect and analyze data that is indicative of the operational characteristics of machines along a testing route within the manufacturing plant. If the collected data indicates that there may be a problem with the operation of a machine, the operator may run “expert” modules to setup the analyzer  10  to collect further data to help in finding the nature and cause of the problem. It is also possible for the operator to determine an expert module should be run before any data has been collected. These expert modules are described in more detail below. 
     The analyzer  10  includes a keyboard  14  or other form of user interface disposed on the face of the analyzer  10  adjacent to a display  12 . Control of the analyzer  10  is achieved through the keyboard  14  in combination with the display  12 . In a typical operation, set-up conditions for a number of machines on a testing route are downloaded into the analyzer  10  from a base computer through a connector  16  located at the top of the analyzer  10 . Connector  16  is preferably, but not limited to, an RS-232 compatible communications port that is also used as a sensor input port to receive signals from sensors, such as vibration transducers. A connector  17  provides an additional input channel for receiving signals, such as an RPM signal from a tachometer. Using the keyboard  14  and the display  12 , the operator may cause the analyzer  10  to incrementally step through the downloaded route of machines, or independent analyzer functions may be invoked that are totally independent of the route. 
     Shown in FIG. 2 is a simplified block diagram of the analyzer  10 . The analyzer  10  includes a sensor  18 , such as an acceleration, velocity, or displacement transducer. The sensor  18  produces an analog signal, such as a vibration signal, that is provided to an analog conditioning circuit  20 . Preferably, the analog conditioning circuit  20  performs input control, analog filtration, analog integration, amplification, and DC offset functions to produce a conditioned analog signal. The conditioned analog signal is provided to a digital conditioning circuit  22 . In the preferred embodiment of the invention, the digital conditioning circuit  22  Sigma-Delta modulates and noise shapes the conditioned analog signal, converts the analog signal into to a digital signal, and digitally filters and digitally decimates the digital signal to produce a conditioned digital signal. The conditioned digital signal is provided to a data processor  24  which processes the digital signal as described in more detail hereinafter. The data processor  24  also controls the digital conditioning circuit  22  and the analog conditioning circuit  20 . Also connected to the data processor  24  are a memory device  26 , the display  12 , and the keyboard  14 . The display  12  preferably is a luminous display, such as, but not limited to, a display manufactured by Samsung under model number 87-203-0123. In the preferred embodiment, the keyboard  14  is a membrane matrix-type keyboard. Preferably, the analyzer  10  also includes a PCMCIA connector  28  coupled to the processor  24  for receiving an external PCMCIA memory card  30 . 
     The analyzer  10  also includes an interface  32 , such as an RS-232 interface or other form of communications interface, to provide for interfacing the analyzer  10  with a base computer  34 . Using the interface  32 , data collected by the analyzer  10  may be downloaded to the base computer  34  for storage and further analysis. Also, test setup information for machines on the route may be uploaded from the base computer  34  to the analyzer  10  through the interface  32 . 
     Preferably, an input for an additional sensor, such as a tachometer, is also provided as shown in FIG.  2 . This additional sensor input is also referred to herein as a tachometer input  36 . 
     In the preferred embodiment of the invention, the analyzer  10  is a hand-held data collector and analyzer such as described in U.S. Pat. No. 5,633,811, and such as manufactured by Computational Systems, Inc., of Knoxville, Tenn., under the model number 2120. However, it will be understood that other types of analyzers may be employed in accordance with the invention. 
     In typical operation, route information is downloaded through the interface  32  from the base computer  34  to the data processor  24  which stores the route information in system memory  26 . The route information typically includes a list of machines to be tested, and a number of test points specified for each machine on the route. For each test point, set-up parameters and data storage parameters are listed. The set-up parameters include such things as the type of sensor  18  to be used, the preferred measurement units, the frequency range of interest, the type of data to be displayed, and the specific data to be stored. The set-up parameters also include other parameters associated with the measurement point, such as the identity of the machine, the identity of the measurement point, a description of the measurement point, and the date and time of the test. 
     In a typical machine testing operation, the test operator uses the analyzer  10  to collect data at a measurement point on a machine, such as at a motor bearing. The routine data collected at this motor bearing measurement point may indicate to the test operator a possible problem with the motor bearing. To further analyze the problem, the operator presses an expert activation button on the face of the analyzer  10 , such as the Analyze button  38  shown in FIG.  1 . (In a future analyzer to be released by Computational Systems, Inc. of Knoxville, Tenn. under Model No. 2120A, this button  38  will be labeled “Analysis Expert.”) When the Analyze button  38  is pressed, the data processor  24  runs an expert selection routine that provides the operator with a list of expert modules from which the operator may choose for help in further analyzing the problem. Preferably, as shown in FIG. 3, the expert selection routine generates the list of expert modules on the display  12 , and the operator may select one of the modules by scrolling through the list to highlight a desired module and pressing an ENTER key  40  on the keyboard  14 . 
     In the preferred embodiment of the invention, the analyzer  10  includes the expert modules listed in Table I. Preferably, these expert modules are an integral part of the firmware stored in the memory  26  of the analyzer  10  when the analyzer  10  is manufactured. Additionally, it is anticipated that the analyzer  10  may be updated with newly-developed expert modules by uploading the new modules through the interface port  32 . 
     
       
         
               
               
             
           
               
                 TABLE I 
               
               
                   
               
               
                 Expert 
                   
               
               
                 Module 
                 Description 
               
               
                   
               
             
             
               
                 High 
                 Used to investigate higher vibrational frequencies which appear 
               
               
                 Fre- 
                 to the right hand side of the vibration spectrum or beyond. 
               
               
                 quency 
                 Useful when problems may be suspected beyond the maximum 
               
               
                 Analy- 
                 frequency (F max ) of the routine route data collected. This expert 
               
               
                 sis 
                 module is useful when data in the high frequencies of the route 
               
               
                   
                 spectrum begin to appear as if they are on a rising slope beyond 
               
               
                   
                 F max  or if the HDF parameter or the overall analog vibration 
               
               
                   
                 reading is in alarm. 
               
               
                 High 
                 Used to increase the resolution in the spectral data to aid in 
               
               
                 Resolu- 
                 viewing closely-spaced spectral peaks. 
               
               
                 tion 
               
               
                 Analy- 
               
               
                 sis 
               
               
                 Bear- 
                 Used when gearing or anti-friction bearing problems are 
               
               
                 ing/ 
                 suspected. This expert can also be used in slow speed 
               
               
                 Gear 
                 applications. Is typically used with a high-frequency 
               
               
                 Peak 
                 vibration sensor (10000-15000 Hz upper frequency limit) 
               
               
                 Vue 
                 which is placed in the radial (horizontal) or axial position in 
               
               
                 Analy- 
                 the load zone of the suspect bearing. 
               
               
                 sis 
               
               
                 Low 
                 Used to observe very low turning speed and/or rolling 
               
               
                 Fre- 
                 element bearing frequencies - usually below 10 Hz. 
               
               
                 quency 
                 Incorporates Slow Speed Technology (SST) as described in 
               
               
                 Analy- 
                 U.S. Pat. No. 5,646,350 to enhance the low frequency data 
               
               
                 sis 
                 by correcting for aspects of the analog integration. The 
               
               
                   
                 sensor may be at the same point as routine route 
               
               
                   
                 measurement, but for very low frequency measurements, a 
               
               
                   
                 special low-frequency accelerometer yields better low 
               
               
                   
                 frequency amplitude results. Often this test is performed on 
               
               
                   
                 shafts turning at less than 600 RPM (10 Hz). 
               
               
                 Order 
                 Used when there is difficulty properly identifying machine 
               
               
                 Track- 
                 vibration frequencies because the machine speed is changing 
               
               
                 ing 
                 during data collection which causes the data to be “smeared” 
               
               
                   
                 between adjacent frequency bands. This expert uses a 
               
               
                   
                 reference (tachometer) pulse supplied to the tachometer input 36. 
               
               
                 Syn- 
                 Used when the amount of non-synchronous energy 
               
               
                 chro- 
                 (background vibration) obscures the synchronous frequency 
               
               
                 nous 
                 analysis, or when transmitted vibration from other machines 
               
               
                 Time 
                 is high. This expert also uses a reference pulse at the 
               
               
                 Aver- 
                 tachometer input 36. 
               
               
                 aging 
               
               
                 Bump 
                 Used when machine cannot be turned off, but resonance is 
               
               
                 Test 
                 still suspected and needs to be tested for. Also used to 
               
               
                 With 
                 collect data on one machine whose data may be influenced 
               
               
                 Ma- 
                 by other equipment running nearby, and then shut down the 
               
               
                 chine 
                 machine to which the sensor is attached and let the analyzer 
               
               
                 Run- 
                 remove the contribution of the other nearby equipment. 
               
               
                 ing 
               
               
                 Bump 
                 Used when high vibration levels are unexplained. May be 
               
               
                 Test 
                 broad or discrete in nature. A rubber tipped hammer may be 
               
               
                 with 
                 used used to impact the machine near the sensor attachment 
               
               
                 Ma- 
                 point, and in the same direction as the sensor. For best 
               
               
                 chine 
                 results with this type of test, the machine in question should 
               
               
                 Off 
                 be shut off. This is because the operational vibration 
               
               
                   
                 amplitudes are usually higher in amplitude than the vibration 
               
               
                   
                 caused by impacting the machine with rubber tipped 
               
               
                   
                 hammer. 
               
               
                 Coast- 
                 Used to check for resonance during the machine coast down. 
               
               
                 down 
                 Sensor is left in place and equipment is turned off 
               
               
                 (Peak 
                 immediately after data collection begins. If a resonant 
               
               
                 Hold) 
                 frequency is suspected in the route spectrum, then the 
               
               
                   
                 frequency of the suspected resonance can be marked and this 
               
               
                   
                 frequency used to generate the F max  in the displayed 
               
               
                   
                 spectrum. 
               
               
                 Peak 
                 This expert may also be used to confirm resonance. This test 
               
               
                 Phase 
                 requires a tachometer pulse at the tachometer input 36 whose 
               
               
                 Coast- 
                 source is the shaft turning speed. The goal is to have the 
               
               
                 down 
                 operational vibration excite the resonance frequencies in the 
               
               
                   
                 system as the equipment coasts to a stop. The expert will 
               
               
                   
                 provide the integer multiple of the turning speed frequency 
               
               
                   
                 to be monitored during the coast down. 
               
               
                 Turn- 
                 Used to confirm a shaft turning speed frequency. The expert 
               
               
                 ing 
                 collects a spectrum and detects the largest peak closest to the 
               
               
                 Speed 
                 frequency that the operator enters as the suspected turning 
               
               
                 Detec- 
                 speed. This test can also be invoked intelligently by the 
               
               
                 tion 
                 analyzer if the equipment to be monitored has been defined 
               
               
                   
                 as a variable speed machine. 
               
               
                 Rotor 
                 Used when rotor bar defects are suspected. A current clamp 
               
               
                 Bar 
                 is placed around one wire of the three phase power supplied 
               
               
                 Test 
                 to the machine under test. A current signal from the current 
               
               
                 (Cur- 
                 clamp is provided as an input to the analyzer 10. 
               
               
                 rent) 
               
               
                 Cross- 
                 Used to determine the phase shift between two sensor 
               
               
                 Channel 
                 locations at a particular frequency. This expert may be used 
               
               
                 Ampli- 
                 to confirm misalignment, imbalance, soft foot, and 
               
               
                 tude/ 
                 resonance. This expert requires that accelerometers be 
               
               
                 Phase 
                 placed at each measurement location. If testing for 
               
               
                   
                 imbalance or resonance, one sensor is placed in the vertical 
               
               
                   
                 direction and the other in the horizontal direction at the 
               
               
                   
                 bearing location. If testing for misalignment, the sensors are 
               
               
                   
                 placed in the same orientation (direction) on either side of 
               
               
                   
                 the coupling. 
               
               
                 Orbit 
                 Used to plot movement of a shaft centerline for orbit 
               
               
                 Plot 
                 analysis. Two sensors are mounted 90 degrees apart at a 
               
               
                   
                 bearing location in the radial direction. This expert 
               
               
                   
                 particularly useful with sleeve bearings and displacement 
               
               
                   
                 probes, but it can also be used with accelerometers. A large 
               
               
                   
                 diameter circle can mean imbalance, a sharp oval can mean 
               
               
                   
                 resonance, and a stationary circle within a circle can mean 
               
               
                   
                 misalignment. 
               
               
                   
               
             
          
         
       
     
     If the operator needs help in deciding which expert module should be used to further analyze a problem, the operator may select a “help” routine associated with the expert selection routine. In the preferred embodiment of the invention, the help routine provides suggestions for the appropriate expert module to use based on the particular situation, such listed in Table II. 
     
       
         
               
               
             
           
               
                 TABLE II 
               
               
                   
               
               
                 Situation 
                 Suggested Expert Module(s) 
               
               
                   
               
             
             
               
                 Unknown sub-synchronous data 
                 High Resolution Analysis 
               
               
                   
                 Low Frequency Analysis 
               
               
                 Synchronous data confirmation: 
                 Synchronous Time Averaging 
               
               
                 unbalance, misalignment, looseness 
                 High Resolution Analysis (2 × TS 
               
               
                   
                 peak marked) 
               
               
                 Confirming imbalance vs. resonance 
                 Bump Test (Machine Running) 
               
               
                   
                 Bump Test (Machine Off) 
               
               
                   
                 High Resolution Analysis (1 × TS 
               
               
                   
                 peak marked) 
               
               
                 Non-synchronous vibration 
                 High Frequency Analysis 
               
               
                   
                 Synchronous Time Averaging 
               
               
                 High frequency 
                 High Frequency Analysis 
               
               
                 Resonance suspected 
                 Bump Test (Machine Running) 
               
               
                   
                 Bump Test (Machine Off) 
               
               
                   
                 Coastdown (Peak Hold) 
               
               
                   
                 Peak/Phase Coastdown 
               
               
                 Resonance suspected - large machine 
                 Peak Hold Coastdown - if no 
               
               
                 to be shut down 
                 tachometer signal available 
               
               
                   
                 Peak/Phase Coastdown- if tacho- 
               
               
                   
                 meter signal available 
               
               
                 Electrical 
                 High Resolution Analysis (2 × TS 
               
               
                   
                 peak marked) 
               
               
                   
                 High Resolution Analysis (1 × TS 
               
               
                   
                 peak marked) 
               
               
                   
                 Rotor Bar Test 
               
               
                 Rolling element bearing failure 
                 Bearing/Gear PeakVue Analysis 
               
               
                   
                 High Frequency Analysis 
               
               
                 Machine speed varying during data 
                 Order Tracking 
               
               
                 collection 
               
               
                 Unsure of turning speed 
                 Turning Speed Detection 
               
               
                 Gear problems suspected 
                 Bearing/Gear PeakVue Analysis 
               
               
                   
                 High Resolution Analysis 
               
               
                   
               
             
          
         
       
     
     When the operator has selected one of the expert modules, such as the Bearing/Gear Analysis expert, the selected expert is executed by the processor  24 . When executed, the selected expert module determines setup parameters for use in setting up the analyzer  10  to collect data, in this example for bearing fault detection data. Thus, the expert modules make intelligent decisions for the operator as to what values of the setup parameters to use in setting up the analyzer  10  to collect data for further analysis of a suspected problem. Since, the operator need not make decisions about the selection of the setup parameters, the operator need not be highly skilled in machine testing techniques. The operator need only be able to follow the instructions and suggestions provided by the analyzer  10 . 
     Table III provides a summary of the setup parameters that are determined by the expert modules. 
     
       
         
               
               
               
             
           
               
                 TABLE III 
               
               
                   
               
               
                 Parameter 
                   
                 Default 
               
               
                 Name 
                 Description 
                 Value* 
               
               
                   
               
             
             
               
                 Frequency 
                 The maximum frequency in HZ of the spectrum to 
                 no 
               
               
                   
                 be collected; also referred to as F max . 
                 default 
               
               
                 Low 
                 The minimum frequency in HZ of the spectrum to 
                 0.0 
               
               
                 Cutoff 
                 be displayed; also referred to as F min . 
               
               
                 Lines 
                 The number of lines of resolution to be used in the 
                 no 
               
               
                   
                 spectral data collection. 
                 default 
               
               
                 Window 
                 A multiplying factor used to shape the waveform 
                 Han- 
               
               
                   
                 data. 
                 ning 
               
               
                 Averages 
                 The number of samples or blocks of the data to be 
                 4   
               
               
                   
                 collected. 
               
               
                 Init Setup 
                 Allows the data collection to reproduce the route 
                 no 
               
               
                   
                 point settings. 
               
               
                 Integ 
                 Determines whether or not the data is integrated di- 
                 digital 
               
               
                 Mode 
                 gitally in the spectrum or analog in the waveform. 
               
               
                 Units 
                 The display units of the spectrum; can also imply 
                 no 
               
               
                   
                 the units of the waveform if analog integration was 
                 default 
               
               
                   
                 selected. 
               
               
                 Averaging 
                 The method used to average together all of the 
                 normal 
               
               
                 Mode 
                 samples specified by the Averages parameter. 
               
               
                 Trig Mode 
                 The event that must occur for data to be collected. 
                 off 
               
               
                 Trig Level 
                 The amplitude of the trigger event. 
                 0.0 
               
               
                 % Pre-trig 
                 The amount of time data to be included in the 
                 0.0 
               
               
                   
                 sample BEFORE the trigger event occurred. 
               
               
                 Fixed 
                 The maximum amplitude range of the analyzer. 
                 0.0 
               
               
                 Scale 
                   
                 (auto) 
               
               
                 Range 
               
               
                 SST 
                 Controls the usage for the Slow Speed Technology 
                 off 
               
               
                   
                 correction factor. 
               
               
                 A- 
                 Adjusts the ⅓ octave airborne noise data to reflect 
                 off 
               
               
                 Weighting 
                 how this data would be heard by the human ear. 
               
               
                 Triax 
                 Allows for use of a sensor that can measure three 
                 off 
               
               
                 Control 
                 vibrational axis simultaneously. 
               
               
                 Demodu- 
                 Enables the demodulation method of high frequency 
                 off 
               
               
                 lation 
                 analysis to be used. 
               
               
                 PeakVue 
                 Enables the PeakVue technology to be used. 
                 off 
               
               
                 Prefilter 
                 Allows for selection of the appropriate high pass 
                 none 
               
               
                   
                 filter value to be used in demodulation and PeakVue 
               
               
                   
                 functions. 
               
               
                 Order 
                 Multiple of turning speed to be monitored. 
                 1   
               
               
                 Bandwidth 
                 The range of frequencies to be measured. This range 
                 0.1 
               
               
                 (BW) 
                 will have the Order frequency in the center of the 
               
               
                   
                 range. A value of 0.1 for the bandwidth means a 
               
               
                   
                 10% range (+5% and −5% around the Order value. 
               
               
                   
                 For example, if the Order value is 1 and the turning 
               
               
                   
                 speed is 30 Hz, then the bandwidth will be from 27 
               
               
                   
                 Hz to 33 Hz for a bandwidth of 0.1. 
               
               
                 Averager 
                 If set to yes, all of the data samples are averaged 
                 no 
               
               
                 Enabled 
                 together. If set to no, the data will be displayed as 
               
               
                   
                 unaveraged monitored data. 
               
               
                 Minimum 
                 If the turning speed drops below this threshold, then 
                 0   
               
               
                 RPM 
                 the data collection will stop. 
               
               
                 Tach Time 
                 Setting to yes disables a tach time-out message. This 
                 yes 
               
               
                 Out 
                 means that data collection may continue even if the 
               
               
                   
                 tachometer signal is disrupted during a test. 
               
               
                   
               
               
                 *Values indicated are default values common to all expert modules.  
               
             
          
         
       
     
     Tables IV, V, VI, and VII below indicate the values of the analyzer setup parameters for the High Resolution, Bearing/Gear PeakVue, Bump Test (Machine Off), and Peak Phase Coastdown expert analysis modules, respectively. The three right-most columns of these tables indicate the values of the setup parameters for three situations in which the expert modules may be used. In one situation, the operator may have just performed a routine test at a particular test point of a machine on a route, collected route data at the measurement point, and sees something in the route data indicative of a problem with the machine. At that point, the operator may activate an expert module to gather more information about the nature of the problem. In this situation, since route data has been collected, the selected expert module automatically sets up the analyzer  10  using the values listed in one of the two “Route Data” columns: “Route Data, No Marked Frequency” or “Route Data, Marked Frequency”. 
     When an operator has collected vibration data at a measurement point along a route, and is viewing the FFT vibration spectrum on the display  12  of the analyzer  10 , there may be a particular frequency, or range of frequencies, at which the operator wishes to focus the analysis. For example, there may be a peak in the vibration spectrum that the operator would like to view at a higher resolution. In that situation, the operator may mark the frequency of the peak using a frequency marking function of the analyzer  10 . In the preferred embodiment of the invention, the keyboard  14  of the analyzer  10  includes left and right arrow keys  42  (FIG. 1) which, when pressed, move a cursor on the display  12  from one frequency to the next in the displayed spectrum. Using the arrow keys  42 , the operator may place the cursor on or near a peak of interest in the frequency spectrum. Then, by pressing a MARK key  44  on the keyboard  14 , the operator marks or designates the frequency corresponding to the position of the cursor. The marked frequency is also referred to herein as F MARK . 
     If a frequency in the spectrum has been marked, the selected expert module automatically sets up the analyzer  10  using the values listed in the “Marked Frequency” column. If a frequency in the spectrum has not been marked, the selected expert module automatically sets up the analyzer  10  using the values listed in the “Route Point, No Marked Frequency” column. 
     In another situation, the operator may wish to use one of the expert modules to perform a test without having first loaded a route measurement point for the data to be collected at a particular measurement point. Such a test may be referred to as an “off route” test. In this situation, since no route measurement point exists, the selected expert module sets up the analyzer  10  using the values listed in the “No Route Point” column. 
     Thus, using the expert modules, the operator need not manually set any of the test setup parameters. The expert modules do this automatically based on the particular situation. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE IV 
               
             
             
               
                   
               
               
                 High Resolution Expert Parameters 
               
             
          
           
               
                 Parameter 
                 Value If No 
                 Value If Route Point; 
                 Marked 
               
               
                 Name 
                 Route Point 
                 No Marked Frequency 
                 Frequency 
               
               
                   
               
               
                 Frequency 
                 1600 Hz 
                 Route F MAX   
                 See FIG. 5. 
               
               
                 Low Cutoff 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Lines 
                 6400 
                 4 × Route Lines 
                 See FIG. 5. 
               
               
                 Window 
                 Hanning 
                 Hanning 
                 Hanning 
               
               
                 Averages 
                 4 
                 4 
                 4 
               
               
                 Init Setup 
                 No 
                 No 
                 No 
               
               
                 Integ Mode 
                 Digital 
                 Route Setting 
                 Route Setting 
               
               
                 Units 
                 Velocity 
                 Route Setting 
                 Route Setting 
               
               
                 Averaging 
                 Normal 
                 Normal 
                 Normal 
               
               
                 Mode 
               
               
                 Trig Mode 
                 Off 
                 Off 
                 Off 
               
               
                 Trig Level 
                 0.0 
                 0.0 
                 0.0 
               
               
                 % Pre-trig 
                 0 
                 0 
                 0 
               
               
                 Fixed Scale 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Range 
               
               
                 SST 
                 No 
                 No 
                 No 
               
               
                 A-Weighting 
                 No 
                 No 
                 No 
               
               
                 Triax Control 
                 Off 
                 Off 
                 Off 
               
               
                 Demodulation 
                 No 
                 No 
                 No 
               
               
                 PeakVue 
                 No 
                 No 
                 No 
               
               
                 Prefilter 
                 Off 
                 Off 
                 Off 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE V 
               
             
             
               
                   
               
               
                 Bearing/Gear PeakVue Expert Parameters 
               
             
          
           
               
                 Parameter 
                 Value If No 
                 Value If Route Point; 
                 Marked 
               
               
                 Name 
                 Route Point 
                 No Marked Frequency 
                 Frequency 
               
               
                   
               
               
                 Frequency 
                 1000 Hz 
                 1000 Hz 
                 &gt; or equal to 
               
               
                   
                   
                   
                 F MARK   
               
               
                 Low Cutoff 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Lines 
                 1600 
                 1600 
                  F MAX   
               
               
                   
                   
                   
                 {overscore ( 1 HZ)} 
               
               
                 Window 
                 Hanning 
                 Hanning 
                 Hanning 
               
               
                 Averages 
                 4 
                 4 
                 4 
               
               
                 Init Setup 
                 No 
                 No 
                 No 
               
               
                 Integ Mode 
                 Digital 
                 Digital 
                 Digital 
               
               
                 Units 
                 Acceleration 
                 Acceleration 
                 Acceleration 
               
               
                 Averaging 
                 Normal 
                 Normal 
                 Normal 
               
               
                 Mode 
               
               
                 Trig Mode 
                 Off 
                 Off 
                 Off 
               
               
                 Trig Level 
                 0.0 
                 0.0 
                 0.0 
               
               
                 % Pre-trig 
                 0 
                 0 
                 0 
               
               
                 Fixed Scale 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Range 
               
               
                 SST 
                 No 
                 No 
                 No 
               
               
                 A-Weighting 
                 No 
                 No 
                 No 
               
               
                 Triax Control 
                 Off 
                 Off 
                 Off 
               
               
                 Demodulation 
                 No 
                 No 
                 No 
               
               
                 PeakVue 
                 Yes 
                 Yes 
                 Yes 
               
               
                 Prefilter 
                 1000 HZ 
                 1000 HZ 
                 ≧F MAX   
               
               
                   
                 high-pass 
                 high-pass 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE VI 
               
             
             
               
                   
               
               
                 Bump Test (Machine Off) Expert Parameters 
               
             
          
           
               
                 Parameter 
                 Value If No 
                 Value If Route Point; 
                 Marked 
               
               
                 Name 
                 Route Point 
                 No Marked Frequency 
                 Frequency 
               
               
                   
               
               
                 Frequency 
                 400 Hz 
                 Route F MAX   
                 2.5 × F MARK   
               
               
                 Low Cutoff 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Lines 
                 400 
                 F MAX   
                 F MAX   
               
               
                   
                   
                 {overscore (1 HZ)} 
                 {overscore (1 HZ)} 
               
               
                 Window 
                 Uniform 
                 Uniform 
                 Uniform 
               
               
                 Averages 
                 6 
                 6 
                 6 
               
               
                 Init Setup 
                 No 
                 No 
                 No 
               
               
                 Integ Mode 
                 Digital 
                 Digital 
                 Digital 
               
               
                 Units 
                 Acceleration 
                 Acceleration 
                 Acceleration 
               
               
                 Averaging 
                 Normal 
                 Normal 
                 Normal 
               
               
                 Mode 
               
               
                 Trig Mode 
                 Pre-trigger 
                 Pre-trigger 
                 Pre-trigger 
               
               
                 Trig Level 
                 0.5 
                 0.5 
                 0.5 
               
               
                 % Pre-trig 
                 10 
                 10 
                 10 
               
               
                 Fixed Scale 
                 Full Scale 
                 Full Scale 
                 Full Scale 
               
               
                 Range 
               
               
                 SST 
                 No 
                 No 
                 No 
               
               
                 A-Weighting 
                 No 
                 No 
                 No 
               
               
                 Triax Control 
                 Off 
                 Off 
                 Off 
               
               
                 Demodulation 
                 No 
                 No 
                 No 
               
               
                 PeakVue 
                 No 
                 No 
                 No 
               
               
                 Prefilter 
                 Off 
                 Off 
                 Off 
               
               
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE VII 
               
             
             
               
                   
               
               
                 Peak Phase Coastdown Expert Parameters 
               
             
          
           
               
                 Parameter 
                 Value If No 
                 Value If Route Point; 
                 Marked 
               
               
                 Name 
                 Route Point 
                 No Marked Frequency 
                 Frequency 
               
               
                   
               
             
          
           
               
                 Order 
                 1 
                 1 
                 Next highest RPM 
               
               
                   
                   
                   
                 multiple above 
               
               
                   
                   
                   
                 F MARK   
               
               
                 Bandwidth 
                 0.1 
                 0.1 
                 0.1 
               
               
                 Averager 
                 No 
                 No 
                 No 
               
               
                 enabled 
               
               
                 Minimum 
                 0 
                 0 
                 0 
               
               
                 RPM 
               
               
                 Tach Time 
                 Yes 
                 Yes 
                 Yes 
               
               
                 Out 
               
               
                 Full Scale 
                 50 
                 50 
                 50 
               
               
                 Range 
               
               
                 Integ Mode 
                 Digital 
                 Digital 
                 Digital 
               
               
                 Units 
                 Sensor 
                 Route Units 
                 Route Units 
               
               
                   
               
             
          
         
       
     
     High Resolution Expert 
     The High Resolution expert is used to increase the resolution, or number of lines, in the spectral data that is displayed in the display  12 . The test operator may use this expert when a routine route test has just been performed and the operator sees something in the spectral data from the test that causes him to want to examine a portion of the frequency spectrum in more detail. 
     FIG. 4A depicts an example of how the test data from the routine route test appears on the display  12 . The upper portion of the display  12  shows a time-domain waveform of the just-collected data. Note that the scale of the time-domain data is from 0 to 400 milliseconds. The lower portion of the display  12  shows the frequency spectrum produced by an FFT of the time-domain data. Note that F MIN  is 5 HZ and F MAX  is 2000 HZ in the example of FIG.  4 A. 
     FIG. 4B depicts a screen as it may appear on the display  12  indicating some of the setup parameters that were used in collecting the data shown in FIG.  4 A. Note that the Lines parameter was set to 800 when the spectral data of FIG. 4A was collected. Thus, the frequency resolution of the spectral route data shown in FIG. 4A is 2000 HZ÷800 lines=2.5 HZ/line. This frequency resolution is also referred to herein as xRes. 
     Referring now to the flowchart of FIG. 5, the function of the High Resolution expert according to a preferred embodiment of the invention is explained. When the operator has selected the High Resolution expert from the selection screen (FIG. 3) and pressed the ENTER button  40  on the analyzer  10  (FIG.  1 ), the processor  24  begins execution of the High Resolution expert analysis module (step  100 ). First, F MAX  is set to 1600 HZ and Lines is set to 6400 (step  102 ). The expert module then determines whether a route measurement point exists (step  104 ). If so, F MAX  is set to be equivalent to the F MAX  that was used in the route setup information, and xRes is set to be equivalent to the resolution of the route spectral data as specified by the route measurement point setup information(step  106 ). In this example, F MAX  is 2000 HZ and xRes is 2.5 HZ. Processing then continues at step  108 . 
     If a route measurement point exists (step  104 ), the values of Lines and F MAX  remain unchanged, and processing continues at step  108 . 
     With continued reference to FIG. 5, the expert module next determines whether a frequency in the displayed spectrum has been marked (step  108 ). If not, Lines is set according to:              Lines   =         4   ×     F   MAX       xRes                       (     step                 110     )     .               (   1   )                                
     For the current example where no frequency has been marked, Lines is determined according to:        Lines   =         4   ×   2000                 HZ       2.5                 HZ       =   3200.                            
     The expert analysis module then causes the analyzer  10  to acquire a new set of frequency spectral data (step  112 ) with F MAX  set to 2000 HZ and Lines set to 3200. It will be appreciated that the phrase “frequency spectral data” refers to a series of data points, each consisting of an amplitude value, such as a vibration or acceleration amplitude value, associated with a frequency value. The new set of spectral data collected by the expert module is shown in the display screen of FIG. 6A, and a portion of the setup parameters used by the expert module in collecting the data are depicted in the display screen of FIG.  6 B. Note that in order to increase the spectral resolution, the parameters set up by the expert module caused the analyzer  10  to collect data over a 0.8 second time period, where in the route test the time period was 0.4 seconds. Note also that Lines is set to 3200 in FIG.  6 B. 
     If a frequency in the displayed spectrum is marked (step  108 ), F MAX  is set equal to F MARK , and xRes is set equal to the frequency resolution of the marked spectrum (step  114 ). If F MARK  is less than half of F MAX  (step  116 ), F MAX  is halved (step  118 ). If F MARK  is still less than half of F MAX  (step  120 ), F MAX  is halved again (step  122 ), and processing continues at step  124 . If F MARK  is not less than half of F MAX  at step  116  or step  120 , processing continues at step  124 . 
     If four times F MAX  divided by xRes is less than or equal to 6400 (step  124 ), then processing continues with steps  110  and  112  as described above. If four times F MAX  divided by xRes is not less than or equal to 6400 (step  124 ), then the expert module determines whether F MARK  is less than or equal to 30 HZ (step  126 ). 
     If F MARK  is less than or equal to 30 HZ (step  126 ), F MAX  is set to 40 HZ and Lines is set to 6400 (step  128 ), and the analyzer  10  acquires a new set of frequency spectral data (step  112 ). If F MARK  is not less than or equal to 30 HZ (step  126 ), the measurement bandwidth, BW, is set equal to xRes times 200, and F LOW  is set equal to F MARK  minus half of BW (step  130 ). The expert analysis module then causes the analyzer  10  to acquire a new set of frequency spectral data (step  132 ) using “true zoom” as described in U.S. Pat. Nos. 5,633,811 and 5,691,924, the entire contents of which are incorporated herein by reference. 
     In general, the results provided by the High Resolution expert module allow viewing of closely spaced peaks in the spectral data. Individual peaks which appear to be merged into a single peak in the original spectrum are more clearly separated in the higher resolution spectrum. For example, trying to distinguish a two-times-turning-speed (2×TS) peak from a two-times-line-frequency (2×LF) peak can be difficult or impossible with low-resolution spectral data. However, using high-resolution spectral data collected by the High Resolution expert, two distinct peaks become visible. If the 2×LF peak is higher in amplitude than the 2×TS peak, this could indicate an electrical problem instead of a misalignment problem. Also, sideband frequencies beside the turning speed peak in an AC induction motor could indicate rotor bar problems. 
     Bearing/Gear PeakVue Expert 
     The Bearing/Gear PeakVue expert module is used when gear or anti-friction bearing problems are suspected in the machine being tested. The test operator may use this expert when a routine route test has just been performed and the operator sees something in the spectral data from the test that causes him to suspect gear or bearing problems. 
     The following description of the invention refers to an analyzer function called PeakVue. PeakVue refers to a signal processing methodology used in machine fault detection for finding peaks in machinery vibration signals. The PeakVue methodology is described in detail in U.S. Pat. No. 5,895,857, the entire contents of which are incorporated herein by reference. 
     FIG. 7 depicts an example of how test data from a routine route test appears on the display  12 . The “Route Values” column of Table VIII lists the setup parameters that were used by the analyzer  10  in collecting the data shown in FIG.  7 . If the test operator sees something in the data of FIG. 7 that makes him want to further investigate possible gear or bearing problems, he presses the Analyze button  38  on the face of the analyzer  10 . The display  12  of the analyzer  10  then preferably displays the screen shown in FIG.  8 . The operator then selects the third analysis expert in the list shown in FIG.  8  and presses the Enter button  40 . 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE VIII 
               
             
             
               
                   
               
               
                 Example of Bearing/Gear PeakVue Expert Parameters 
               
             
          
           
               
                 Parameter 
                 Route Point 
                 Value If Route Point; 
                   
               
               
                 Name 
                 Value 
                 No Marked Frequency 
                 Marked Frequency 
               
               
                   
               
               
                 Frequency 
                 4000 Hz 
                 1000 Hz 
                 2000 Hz 
               
               
                 Low Cutoff 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Lines 
                 1600 
                 1600 
                 3200 
               
               
                 Window 
                 Hanning 
                 Hanning 
                 Hanning 
               
               
                 Averages 
                 4 
                 4 
                 4 
               
               
                 Init Setup 
                 No 
                 No 
                 No 
               
               
                 Integ Mode 
                 Digital 
                 Digital 
                 Digital 
               
               
                 Units 
                 Acceleration 
                 Acceleration 
                 Acceleration 
               
               
                 Averaging 
                 Normal 
                 Normal 
                 Normal 
               
               
                 Mode 
               
               
                 Trig Mode 
                 Off 
                 Off 
                 Off 
               
               
                 Trig Level 
                 0.0 
                 0.0 
                 0.0 
               
               
                 % Pre-trig 
                 0 
                 0 
                 0 
               
               
                 Fixed Scale 
                 0.0 
                 0.0 
                 0.0 
               
               
                 Range 
               
               
                 SST 
                 No 
                 No 
                 No 
               
               
                 A-Weighting 
                 No 
                 No 
                 No 
               
               
                 Triax 
                 Off 
                 Off 
                 Off 
               
               
                 Control 
               
               
                 Demodu- 
                 No 
                 No 
                 No 
               
               
                 lation 
               
               
                 PeakVue 
                 No 
                 Yes 
                 Yes 
               
               
                 Prefilter 
                 Off 
                 1000 HZ high-pass 
                 2000 HZ high-pass 
               
               
                   
               
             
          
         
       
     
     Referring now to the flowchart of FIG. 9, the operation of the Bearing/Gear PeakVue expert according to a preferred embodiment of the invention is explained. When the operator has selected the Bearing/Gear expert and pressed the Enter button  40  on the analyzer  10 , the processor  24  begins execution of the Bearing/Gear PeakVue expert module (step  200 ). First, F MAX  is set to 1000 HZ, acceleration measurement units are selected, and the PeakVue function is enabled (step  202 ). The expert module then determines whether a frequency in the spectrum has been marked (step  204 ). If not, F MAX  remains unchanged at 1000 HZ. The expert module then enables a digital high-pass prefilter and sets the cut-off frequency of the prefilter, F CO , to be greater than or equal to F MAX  (step  208 ). The Lines parameter is then selected to provide a frequency resolution of the spectral data of at least one HZ per line (step  210 ). For example, in the preferred embodiment, if no frequency is marked, the Lines parameter is set to 1600. The frequency spectrum data is then acquired (step  212 ). 
     FIG. 10 depicts the display screen showing the spectral data collected by the Bearing/Gear PeakVue expert module for the case of no marked frequency. 
     If, at step  204  of FIG. 9, the expert module determines that a frequency in the spectrum was marked, F MAX  is set to be greater than or equal to F MARK  (step  206 ). For example, as shown in the display screen depicted in FIG. 11, if the marked frequency is 1355 HZ, the expert module preferably sets F MAX  to 2000 HZ. The digital high-pass prefilter is then enabled with a cut-off frequency, F CO , greater than or equal to 2000 HZ (step  208 ). In this example, F CO  is set at 2000 HZ. The frequency spectrum data is then acquired (step  212 ). 
     FIG. 12 depicts the display screen showing the spectral data collected by the Bearing/Gear PeakVue expert module for the case of a marked frequency of 1355 HZ. 
     In general, the results provided by the Bearing/Gear PeakVue expert module allow viewing of peaks in the spectral data indicative of bearing and gear defects. The bearing defect frequencies will appear at their fundamental frequencies in the spectrum. These peaks will be non-synchronous. Generally, gear defects may be identified by the defective gear&#39;s shaft turning speed frequency and harmonics thereof. 
     Bump Test (Equipment Off) 
     The Bump Test (Equipment Off) expert module is used to determine natural resonances in the machine under test. When an observed vibrational amplitude is high, this test may be used to determine whether the high vibration is caused by a high input force, or by a low input force that is increased by resonant amplification. This test is performed by applying an impact force to the machine, typically using a rubber tipped hammer. The hammer impact is preferably applied near the sensor  18 , and in the same direction as the sensor  18  senses. This test is performed while the machine is off since operational vibration amplitudes are usually higher in amplitude than vibration caused by impacting the machine with the hammer. 
     This expert module will be described based upon the following scenario: The test operator starts from a situation where no route parameters are loaded into the analyzer. Thus, there is no prior measurement point information to draw from. The operator will perform the bump test and mark a frequency in the resulting spectral data. The operator will then repeat the test, but the second time the marked frequency will be used in determining the setup parameters to be used in the second data collection. 
     The operator first presses the Analyze button  38  on the analyzer  10 , and proceeds to the second page of the listing of available expert modules, as depicted in the screen display of FIG.  13 . The operator then selects the Bump Test (Equip Off) expert and presses the Enter key  40 . 
     Referring now to FIG. 14, when the operator presses the Enter key  40 , the processor  24  begins execution of the Bump Test (Equipment Off) expert module (step  300 ). In the preferred embodiment, the expert module first sets F MAX  to 400 HZ, selects acceleration units and a uniform window, and sets Averages to 6, Full Scale Range to 20.0, Pre-Trigger to 10%, and Trigger Level to 0.5 (step  302 ). If there is no route data (step  304 ) and no marked frequency (step  306 ), as is the case in the present example, the expert module sets the value of Lines to provide a frequency resolution of at least one HZ per line (step  308 ). Thus, Lines is set to 400 for this example. The frequency spectrum data is then acquired (step  310 ). 
     FIG. 15 depicts the display screen showing the spectral data collected by the Bump Test (Equipment Off) expert module using the setup parameters listed in the “No Route Data” column of Table IX. As depicted in FIG. 16, the test operator designates a frequency of interest at 19.57 HZ by placing the cursor on the peak and pressing the Mark key  44  on the keyboard  14 . Thus, F MARK  is set to 19.57 HZ. 
     To run the bump test again, this time using the marked frequency, the operator again selects the Bump Test (Equipment Off) expert module (FIG. 13) and presses the Enter key  40  (FIG.  1 ). Referring again to FIG. 14, when the Enter key  40  is pressed, the processor  24  begins execution of the Bump Test (Equipment Off) expert module (step  300 ). Again, F MAX  is set to 400 HZ, acceleration units and a uniform window are selected, and Averages is set to 6, Full Scale Range to 20.0, Pre-Trigger to 10%, and Trigger Level to 0.5 (step  302 ). In this case, there is again no route data (step  304 ). However, since there is a marked frequency (step  306 ), the expert module sets F MAX  to be equivalent to 2.5 times F MARK  (step  312 ). In this example, F MAX  is set to 50 HZ. The expert module then sets the value of Lines to provide a frequency resolution of no greater than HZ per line (step  308 ). In this example, Lines is set to 100 which provides a resolution of 0.5 HZ per line. The frequency spectrum data is then acquired again (step  310 ). 
     FIG. 17 depicts the display screen showing the spectral data collected by the Bump Test (Equipment Off) expert module for the case of a marked frequency of 19.57 HZ. In this situation, the expert module used the setup parameters listed in the “No Route Data; Marked Frequency” column of Table IX. 
     As FIG. 17 indicates, the results of the bump test should show a peak at the resonant frequency. Generally, single channel resonance testing requires several tests to confirm the resonant frequency with confidence. The impact of the hammer places a small amount of force into the mechanical system over a wide range of frequencies. The resonance, which occurs over a range of frequencies, naturally amplifies the resulting vibration. The peaks seen in the spectral data represent the resonant frequency. Typically, when these resonant frequencies are known, the machines are operated so as to avoid operational frequencies that coincide with the resonant frequencies, because otherwise the input forces will be amplified causing excessively high vibration. 
     
       
         
               
             
               
               
               
               
             
           
               
                 TABLE IX 
               
             
             
               
                   
               
               
                 Example of Bump Test (Equipment Off) Expert Parameters 
               
             
          
           
               
                   
                 Parameter 
                   
                   
               
               
                   
                 Name 
                 No Route Point 
                 Marked Frequency 
               
               
                   
                   
               
               
                   
                 Frequency 
                 400 Hz 
                 50 HZ 
               
               
                   
                 Low Cutoff 
                 0.0 
                 0.0 
               
               
                   
                 Lines 
                 400 
                 100 
               
               
                   
                 Window 
                 Uniform 
                 Uniform 
               
               
                   
                 Averages 
                 6 
                 6 
               
               
                   
                 Init Setup 
                 No 
                 No 
               
               
                   
                 Integ Mode 
                 Digital 
                 Digital 
               
               
                   
                 Units 
                 Acceleration 
                 Acceleration 
               
               
                   
                 Averaging 
                 Normal 
                 Normal 
               
               
                   
                 Mode 
               
               
                   
                 Trig Mode 
                 Pre-trigger 
                 Pre-trigger 
               
               
                   
                 Trig Level 
                 0.5 
                 0.5 
               
               
                   
                 % Pre-trig 
                 10 
                 10 
               
               
                   
                 Fixed Scale 
                 20 
                 20 
               
               
                   
                 Range 
               
               
                   
                 SST 
                 No 
                 No 
               
               
                   
                 A-Weighting 
                 No 
                 No 
               
               
                   
                 Triax Control 
                 Off 
                 Off 
               
               
                   
                 Demodulation 
                 No 
                 No 
               
               
                   
                 PeakVue 
                 No 
                 Yes 
               
               
                   
                 Prefilter 
                 Off 
                 Off 
               
               
                   
                   
               
             
          
         
       
     
     The Peak Phase Coastdown expert module is also used to determine natural resonances in the machine under test by plotting the amplitude and phase vibration response at the 1×RPM frequency. This test requires use of the tachometer input  36  whose source is the shaft turning speed. The goal is to have the operational vibration excite the resonance frequencies in the system as the machine coasts to a stop after removing power to the machine. The data collection should begin before power is removed. In the preferred embodiment of the invention, this expert module is used when there is route data present. 
     To run the expert, the operator presses the Analyze button  38  on the analyzer  10 , and proceeds to the second page of the listing of available expert modules, as depicted in the screen display of FIG.  18 . The operator then selects the Coastdown (Peak/Phase) expert from the list and presses the Enter key  40 . 
     Referring now to FIG. 19, when the operator presses the Enter key  40 , the processor  24  begins execution of the Peak Phase Coastdown expert module (step  400 ). In the preferred embodiment, the expert module first sets Order to 1.0, bandwidth to 0.1, Minimum RPM to 0, turns averaging off, enables the Tach Timeout, and sets the Full Scale Range to 50.0 (step  402 ). If no frequency has been marked on a previously acquired spectrum (step  404 ), then the expert module proceeds to activate the analyzer  10  to monitor the amplitude peak and phase of the vibration response of the machine (step  406 ). As the analyzer  10  collects the vibration data, the test operator removes power to the machine, so that the machine coasts to a stop. FIG. 20 depicts an example of a screen displayed during the coastdown test. 
     If the test operator had marked a frequency of interest on a previously-collected spectrum, the expert module sets Order according to:          ORDER   =       INT        [     (       F   MARK     RPM     )     ]       +     1                   (     step                 408     )           ,                          
     where RPM is the revolutions per minute of the machine based upon the tachometer signal provided at the tachometer input  36 . For example, as shown in FIG. 21, the operator may have marked a frequency of 80.47 HZ in the route data spectral display. In this situation, if RPM is 30 HZ, Order is determined to be:        ORDER   =         INT        [     (       80.47                 HZ       30                 HZ       )     ]       +   1     =   3.                            
     Thus, in this example, the expert module measures the third harmonic of the turning speed frequency as the machine coasts down. FIG. 22 depicts an example of a screen displayed during the coastdown test when using the marked frequency of 80.47 HZ. 
     The setup parameters used by the expert in performing the coastdown tests, with and without a marked frequency, are listed in Table X. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE X 
               
             
             
               
                   
               
               
                 Example Peak Phase Coastdown Expert Parameters 
               
             
          
           
               
                   
                 Parameter 
                 Route Data; 
                 Route Data; 
               
               
                   
                 Name 
                 No Marked Frequency 
                 Marked Frequency 
               
               
                   
                   
               
             
          
           
               
                   
                 Order 
                 1 
                 3 
               
               
                   
                 Bandwidth 
                 0.1 
                 0.1 
               
               
                   
                 Averager 
                 No 
                 No 
               
               
                   
                 enabled 
               
               
                   
                 Minimum 
                 0 
                 0 
               
               
                   
                 RPM 
               
               
                   
                 Tach Time 
                 Yes 
                 Yes 
               
               
                   
                 Out 
               
               
                   
                 Full Scale 
                 50 
                 50 
               
               
                   
                 Range 
               
               
                   
                 Integ Mode 
                 Digital 
                 Digital 
               
               
                   
                 Units 
                 Velocity 
                 Velocity 
               
               
                   
                   
               
             
          
         
       
     
     As shown in FIGS. 20 and 22, the spectral data collected by the Peak Phase Coastdown expert indicates a peak in the data corresponding to the resonance in the machine under test. An additional benefit of this test is that the phase shift at the multiple of the turning speed may be known. At a resonance, the phase goes through a 180 degree phase shift. This data is very useful in confirming the resonant frequency. 
     Turning Speed Detection 
     The turning speed detection expert module is used in conjunction with measurements taken for variable speed machines, such as variable speed electric motors. If the user is measuring a variable speed machine, the analyzer  10  prompts the user for the equipment turning speed. The analyzer  10  looks for the presence of a tachometer signal at connector  17  (FIG. 1) and if no tach signal is present, the analyzer  10  prompts the user to enter a suspected turning speed of the machine. After the user&#39;s best estimate of turning speed is input, the analyzer  10  collects and analyzes data to determine a detected turning speed. A spectrum is then displayed on the analyzer&#39;s display  12  with the detected turning speed peak marked. The user has the option of accepting or rejecting the detected turning speed. If accepted, the detected turning speed is stored for the equipment and the user returns to the main data collection menu to continue with the collection of route data for the variable speed equipment. The user may also invoke this module by manual selection from the main menu. 
     One benefit of a turning speed detection expert according to the invention is that it enables the analyzer  10  to detect actual turning speed with a high degree of accuracy without the benefit of a tachometer signal. The user simply inputs his best estimate of what the turning speed should be, and the analyzer  10  finds the actual turning speed based on the user&#39;s best estimate. 
     Another feature offered by each of the expert modules is the labeling of spectral data collected by the expert to indicate which expert was used to collect the data. For example, when the Bearing/Gear PeakVue expert is used to collect spectral data, the expert module attaches a label field to the spectral data file that is stored in the memory  26 . When the spectral data file is later downloaded from the memory  26  in the analyzer  10  to a database on the base computer  34 , the label field distinguishes the expert-collected data from standard route data in the database. For example, FIG. 23 depicts a display screen which may be generated by a database or data analysis program running on the base computer. Note that the eighth and ninth spectral data sets listed in FIG. 23 include labels indicating which expert modules were used in collecting the data. 
     The analyzer uniquely identifies the data collected by the Analysis Experts as a “special test” collected by a specific expert. The communications program interprets this unique identification and passes this identification of the “special test” data back to the PC for storage, post analysis, and processing. This allows PC-based expert analysis programs, such as one provided by Computational Systems, Inc. of Knoxville, Tennessee under the trade name Nspectr®, to interpret the “special test” data collected by the specific expert as special data, thus providing for the ability to improve the expert system&#39;s overall diagnosis. 
     It is contemplated, and will be apparent to those skilled in the art from the preceding description and the accompanying drawings that modifications and/or changes may be made in the embodiments of the invention. Accordingly, it is expressly intended that the foregoing description and the accompanying drawings are illustrative of preferred embodiments only, not limiting thereto, and that the true spirit and scope of the present invention be determined by reference to the appended claims.