Abstract:
An operation testing of a temperature sensor of an alarm includes spraying so that the sprayable material is sprayable on the temperature sensor, a temperature decrease due to the spraying is detected, and an operation ability is determined in dependence on the testing.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a testing device for testing operation of a temperature sensor of an alarm or an alarm, and, a method of testing operation of an alarm. 
     It is known that fire alarms in Germany must be tested in accordance with the regulation VDE 0833 at least once per year with respect to its operation. When the fire alarm has a smoke detector and a temperature sensor, then the smoke detector and the temperature sensor must be tested separately with respect to their corresponding functions. The temperature sensor is tested by hot air. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a testing device for operation testing of a temperature sensor of an alarm or an alarm, and a method of operation testing of an alarm, which are further improvements of the existing solutions. 
     In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated in a testing device for operation testing of a temperature sensor of an alarm, which has a testing device for operation testing of a temperature sensor of an alarm, comprising a spraying source with a sprayable material; a testing cup fittable over a temperature sensor; a valve arranged on the spraying source for letting out the sprayable material and extending into said testing cup, the valve having a valve opening adapted to be arranged in a vicinity of the temperature sensor, so that the sprayable material is sprayable on the temperature sensor. 
     It is another object of the present invention to provide a method of operation testing of a temperature sensor of an alarm which includes spraying the temperature sensor with a sprayable material by a testing device; testing a temperature decrease of the spraying with the sprayable material; and indicating an operativeness of the temperature sensor in dependence on the testing. 
     In accordance with the present invention, the temperature sensor is tested with a sprayable material, for example an aerosol, which is sprayed on it and thereby causes a temperature decrease. Therefore, means for providing electrical energy as required in the case of hot air are not needed. The spraying with the sprayable material of the temperature sensor leads to a cooling and thereby to an opposite temperature course to the one which occurs during a fire, which can be easily used as a criterium for a testing model. 
     Moreover, the measurement with aerosol is utilized also for the simultaneous operation test of a smoke detector. Therefore by a single positioning of the testing device, both measuring processes of the smoke detector and the temperature sensor can be performed for testing their operations. This leads to a simplified, faster and easier testing of a fire alarm. 
     It is especially advantageous that in accordance with the present invention the switching of the alarm to a testing mode can be performed either by a central unit connected to the alarm or by a switch located on the alarm or by remote operation or by the alarm itself. Thereby it is guaranteed that the testing mode is recognized and adjusted, and thereby the operation ability of the temperature sensor and in some cases of the smoke detector is tested. 
     In particular, with the use of aerosol and another sprayable material for the operation testing of the temperature sensor, it is possible that the alarm recognizes an operation testing itself, and the fast cooling is performed by spraying of the temperature sensor with aerosol, which otherwise is not expected. A temperature gradient of −10° C./sec can be expected, which does not happen in a normal case. Since many alarms, in particular in professional area, are connected to a central unit, for example through a bus, therefore through the central unit, when the operation testing must be performed, the alarms are signaled so that they are adjusted to the testing mode. 
     A further possibility resides in that, during the triggering of the operation testing process either by the testing device or by an operator remotely, the testing mode of the alarm is activated. 
    
    
     The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view showing a testing device for an alarm in accordance with the present invention; 
     FIG. 2 is a view showing a block diagram of the inventive alarm system, which is connected to a central unit; 
     FIG. 3 is a view showing a block diagram of the alarm in accordance with the present invention, which has a switch or a receiver for activation in the test mode; and 
     FIG. 4 is a flow diagram of a method in accordance with the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A testing of fire alarms, in particular such which are provided with a temperature sensor and a smoke detector and arranged in large halls and buildings where the fire alarm is located a few meters above the ground on the ceiling, is a difficult work. 
     In accordance with the present invention a method for operation testing of temperature sensors is proposed, which is also usable for the operation testing of smoke detectors and is performed for both sensors, namely the temperature sensor and the smoke detector. For this purpose aerosols are utilized, which are sprayed on the temperature sensor and activate there a proportional temperature decrease by the temperature decrease and/or by the evaporation of the drive medium. Furthermore, the aerosol leads to the situation that an available smoke detector is tested with respect to its operation by the aerosol, which imitates a smoke. In order to set a fire alarm into a testing mode, in which it recognizes that an operation testing of the temperature sensor and in some cases of the smoke detector is performed, a central unit connected to the fire alarm, or a switch available on the alarm, or an own intelligence of the alarm are utilized. 
     Aerosols are liquid droplets which are located in a gas, here a drive medium or propellant. They are present as a fog. With a gas flow which is caused by spraying, a pressure reduction and an evaporation of the drive medium is performed, which leads as well known to a proportional temperature decrease. If only a temperature sensor is tested, also another sprayable material can be used, to provide a fast temperature decrease, such as for example water or propanol. 
     FIG. 1 shows the inventive testing device in use with an alarm. An alarm  2  is arranged on a ceiling  1 , which alternatively can be also a wall. The alarm  1  has a temperature sensor  3 . Moreover it is possible that the alarm  2 , which is here formed as a fire alarm, has an additional smoke detector. A smoke detector as conventional can have a labyrinth-like passage, through which the smoke penetrates through the alarm in the event of fire, to reach a measuring chamber were an optical measurement of a smoke detection is performed. 
     A valve  4  is oriented with its opening to the temperature sensor  3 , so that an aerosol which flows out of the opening is sprayed directly onto the temperature sensor  3 . The valve  4  is arranged on a line which is connected to a spraying can  5 . The spraying can  5  contains the aerosol with a propellant which is present in the spraying can  5  as a liquid. The spraying can  5  is located inside a housing  6  of the testing device while the valve  4  is located inside a testing cup  7  which is fitted over the alarm  2  to perform measurements. The housing  6  surrounds the testing cup  7  and is mounted on it. 
     Alternatively it is possible that the spraying can  5  extends into the testing cup  7 , and passages through the testing cup  7  for example for the lines are sealed. Therefore, the aerosol which is sprayed by the valve  4  into the testing cup  7  remains in the testing cup to be ready for the measurement. The testing cup  7  is mounted on the wall or pressed on it. The housing  6  of the testing device is held by a rod  8 . The rod  8  serves as an operator to fit the testing device over the alarm. The testing cup  7  of the housing  6  can be composed of a transparent synthetic plastic material, so that the operator can perform a simple placing of the inventive testing device. It is therefore avoided that the valve  4  abuts against the alarm  2  and can damage the same. The spraying can  5  is mounted on the housing  6 , for example by clamps, so as to provide a possibility for a simple exchange of the spraying can  5 . FIG. 1 does not show means for opening of the valve, which can be formed purely mechanically or electromechanically. 
     FIG. 2 shows a block diagram of a first embodiment of the inventive alarm. A temperature sensor  9  and a smoke detector  10  are connected through their outputs to a signal processing unit  11 , and in particular to the first and second inputs. A data output of the signal processing unit  11  leads to a data input of a processor  12 . A first data input/output of the processor  12  leads to a memory  13 . A second data input/output of the processor  12  leads to a communication block  14 , while a second data input/output of the communication block  14  is connected to a communication line  15 . A data output of the processor  12  leads to a signal processing device  16 , with which the means  17  for optical and acoustic visitation is connected. The means  17  for optical and acoustical reproducing are here a light and a siren, wherein only the light or only the siren can be used or a loudspeaker can be utilized. 
     The sensors, the temperature sensor  9  and the smoke detector  10 , supply signals to the signal processing unit  11 . The signal processing unit  11  amplifies and digitizes these sensor data. Furthermore, the signal processing device  11  forms a multiplex of the signals, which then are transmitted to the processor  12 . 
     The processor  12  performs an analysis of the sensor data, and in a normal operation these sensor data are compared with threshold data to perform a fire detection. These threshold values are stored in the memory  13  which is also used as an operational memory for the processor  12 . 
     If through the communication line  15  a signal is transmitted from a central unit connected to the communication line  15 , that the alarm  2  is switched to a testing mode, then the processor  12  evaluates the testing signals as to whether a normal operation of the sensors  9  and  10  is provided. This is also performed with respect to the threshold value which is in the memory  13 . Alternatively it is possible to transmit these measuring values of the central unit through the communication line  15 , so that the central unit performs the evaluation. When the processor  12  performs the evaluation, it can indicate the same by means  17  for optical and acoustic representation. It the central unit performs this, then the central unit transmits corresponding signal to the alarm  2 , so that moreover by the means  17  for acoustic and optical presentation an available or a failing operation can be indicated. 
     The signal processing unit  16  converts a command coming from the processor  12  into a corresponding signal for the siren and the like. The communication block  14 , here a modem, connects the alarm to the communication line  15 . Alternatively it is possible that the communication block  14  is formed as a bus controller and the communication line  15  is formed as a bus system for example the known LSN bus, interconnectable through the alarm. The signal processing unit unit  11  can be alternatively subdivided into two signal processing units dedicated to the corresponding sensor. It is composed of a corresponding signal amplifier and an analog/digital converter, and digitized signals are assembled in a multiplexer for forming the data flow for the processor  12 . 
     FIG. 3 shows a block diagram of the second embodiment of the alarm. The temperature sensor  9  and the smoke detector  10  are connected correspondingly to the first and second input of the signal processing unit  11 . The signal processing unit  11  is connected to a first data input of the processor  12 . A switch  18  is connected to a second data input of the processor  12 . It indicates whether a testing mode is provided for the alarm  2  or not, and acts so as to switch the alarm  2  to the testing mode. The memory  13  is connected to a data input/output of the processor  12 . The signal processing unit  16  is connected to a data input of the processor  12 , and the means  17  for acoustic and optical indication are connected to the signal processing unit  16 . 
     The switch  18  is formed as a Reed contact. With a Reed contact, a switch element is closed or opened by magnetized springs. Thereby the Reed contact  18  is accessible for an outwardly actuated magnetic fields. Such a magnet is mounted here in the testing device, for example in the housing  6 , for actuation of the Reed contact  18  by this magnet. When then the testing cup  17  is fitted over the alarm  2 , the magnet switches during the fitting of the read contact  18  so that the alarm  2  is switched to the testing mode. Alternatively it is possible to form the switch  18  as an infrared or as a radio interface with a connected electronic system, so that the alarm  2  is switchable to a testing mode by a remote operation with infrared signals or radio signals. For the radio signals, for example a Blue tooth is suitable which is utilized for transmission over short distances. 
     The inventive method for operation testing of the temperature sensor  3  and the alarm  2  is illustrated in form of a flow diagram. In the method step  19  the operator is introduced, in that the operator brings the testing device to the housing  6  and the testing cup  7  over the alarm  2 , which is mounted on the ceiling  1 . The operator uses the rod  8  for this purpose. In the method step  20  the alarm  2  is switched to the testing mode. This is performed either through a remote control operation by the operator as explained above, or by fitting of the testing device, so that the Reed contact  18  is actuated, or by a central unit connected to the alarm  2  which switches the alarm to the testing mode. Alternatively it is possible that the alarm  2  recognizes the signals coming from the temperature sensor  3 , performs an operational testing, and thereby automatically switches in the testing mode. 
     In the method step  21  aerosol is sprayed from the spraying can  5  of the temperature sensor  3 , through the valve  4  which is open by the user and leads to a fast temperature decrease. The processor  12  check this measured temperature increase whether the temperature sensor  3  operates properly. This is performed in the method step  22  which is provided for the temperature measurement and in the method step  23  whether the processor  12  performs the evaluation itself. In some cases the processor  12  performs the switching to the testing mode, if processor  12  detects that it deals with a testing signal. In some cases, also measuring signals of the smoke detector  10  are evaluated, as to whether the smoke detector  10  correctly detects smoke. In the method step  24  it is tested whether the processor determined that a correct operation of the smoke detector  10  and the temperature sensor  9  takes place. If this is the case, then in the method step  26  it is indicated that everything is in order. If this is not the case or the operation of at least one of the sensors  9  and  10  is not correct, then in the method step  25  an acoustic and optical indication is produced by the means  17 . Alternatively, it is possible that it is transmitted additionally or instead to the central control unit. 
     It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. 
     While the invention has been illustrated and described as embodied in testing of a temperature sensor of an alarm, an alarm and a method of operation testing of an alarm, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.