Abstract:
A portable diesel fuel tester and a method of its use are provided. A sample of diesel fuel is placed in a sample tray of the tester. The diesel fuel is heated to a gas state and circulated to a SO 2  sensor by an air pump. The SO 2  sensor determines the level of sulfur in the diesel fuel based on the SO 2  levels. The sulfur level is displayed on an LCD screen for viewing by the user.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to a fuel tester. More particularly, the present invention relates to a portable diesel fuel tester. 
   BACKGROUND OF THE INVENTION 
   Ultra-low sulfur diesel (ULSD) is a new standard that has been proposed by the EPA that effects diesel fuel sold for use on-road. This new regulation pertains to diesel fuel, additives and distillate fuels such as kerosene. The previous low diesel sulfur content was 500 p.p.m. (parts per million). The USLD contains only 15 p.p.m., which is about a 97 percent reduction from the 500 p.p.m. level. 
   The EPA requires that by Dec. 1, 2010, all highway diesel fuel sold will be ULSD. The use of ULSD will decrease emissions of sulfur compounds, which has been linked to acid rain. The decrease in sulfur content (15 p.p.m.) will reduce the replacement of particulate filters, which are being plugged up at the higher sulfur content of 500 p.p.m. The EPA hopes that the new standard will reduce the nitrogen oxide emissions by 2.6 million tons and particulate matter by 110,000 tons per year. Additionally, ULSD is required to be used in the new diesel engines or the warranty of the engines will be voided. 
   There are currently bench size testers that are implemented with a computer that are expensive to purchase and use. The bench size testers are not mobile and thus field inspections cannot be readily be done either at the refineries or the fueling stations. Additionally, the bench size testers require that the samples be sent to its location for analysis and that increases the time in which the results can be made available. The inspections include determining whether there has been sulfur contamination in the fuel refining system or if the fuel is over the legal limit. When sulfur reacts with oxygen it forms SO 2 , which can be used to test the amount of sulfur in the fuel. 
   Accordingly, there is a need for an apparatus and method to test diesel fuel in the field that is cost effective and the results can be determined in the field. 
   SUMMARY OF THE INVENTION 
   The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments provides a vehicle diagnostic device that includes a programmable function key in order to control a function on an emission computer workstation. 
   In accordance with one embodiment of the present invention, a portable diesel fuel tester is provided, which can include a LCD display that displays testing information, a testing chamber for testing the diesel fuel having a door, the door having vent holes that can vent a gas from the testing chamber, a sample tray located in the testing chamber that can receive a sample of diesel fuel to be tested, the sample tray having a heating element that can heat the diesel fuel to the gas state, a SO 2  sensor that senses SO 2  gas generated by the heating of the diesel fuel, an air pump that can circulate the gas of the heated diesel fuel from the sample tray to the SO 2  sensor, a power source for powering the fuel tester, a processor having a software that can operate the tester, wherein the processor can be in communication with the LCD display, the SO 2  sensor, the heating element, the power source and the air pump, and a housing that can house the LCD display, the testing chamber, the sample tray, the SO 2  sensor, the processor, the power source, and the air pump, wherein the housing is configured so that the tester is portable. 
   In accordance with another embodiment of the present invention, a method of testing a sample of diesel fuel is provided and can include depositing a sample of diesel fuel on a sample tray of a portable diesel fuel tester, heating the sample of diesel fuel with a heating element to a gas state that is detectable by a SO 2  sensor, circulating the gas from the sample tray to the SO 2  sensor with an air pump, detecting the gas containing SO 2  with the SO 2  sensor, determining the amount of sulfur in the sample of diesel fuel from the SO 2  gas, and displaying the amount of sulfur in the sample of diesel fuel on a LCD display. 
   In accordance with yet another embodiment of the present invention, a portable diesel fuel tester is provided, which can include a means for displaying testing information, a means for containing testing conditions for a sample of diesel fuel having a door, the door having vent holes that can vent a gas from the means for containing testing conditions, a means for receiving the sample of diesel fuel to be tested, the means for receiving having a means for heating the diesel fuel to the gas state, a means for sensing SO 2  gas generated by the heating of the diesel fuel, a means for circulating the gas of the heated diesel fuel from the means for receiving to the means for sensing, a means for powering the portable diesel fuel tester, a means for processing having a software that operates the tester, wherein the means for processing is in communication with the means for displaying, the means for sensing, the means for heating, means for the powering and the means for circulating, and a means for housing that houses the means for displaying, the means for containing, the means for receiving, the means for sensing, the means for processing, the means for powering, and the means for circulating, wherein the means for housing is configured so that the tester is portable. 
   There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
   In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
   As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a diesel fuel tester according to an embodiment of the invention. 
       FIG. 2  is a block diagram of the components of the tester. 
       FIG. 3  illustrates the steps of the operation of the tester of the present invention. 
   

   DETAILED DESCRIPTION 
   The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a portable diesel fuel tester that can test the sulfur content in the field and display the results to a user. 
     FIG. 1  illustrates a diesel fuel tester  100  according to an embodiment of the invention. The tester is configured and designed to be portable. The tester  100  includes a housing  110  to house the components of the tester including a testing portion  128 , a storage compartment  124 , and power switch  132  and a power source  136 , such as a battery (not shown). The tester further includes an LCD screen  112  mounted on an external surface of the housing for viewing by the user. The LCD displays information including the amount of sulfur in the tested diesel fuel. The LCD can also display instructions on the screen for the user to run the test or display any other information desired. The power source can be an internal or external battery or by plugging into a DC or AC source. 
   Within the housing  110  is a circulating air pump  114  to circulate the air in the testing portion  128  of the tester  100 . A SO 2  sensor  116 , such as sensors available from Alphasense, Ltd in the United Kingdom can be used to measure the amount of sulfur in the tested diesel fuel. A door  120 , made from Plexiglas, for example, is used to introduce the diesel fuel into a testing chamber  130 . The door  120  can include vent holes  118  therein for the vapor (from the vaporized diesel fuel) to escape the testing chamber  130  to reach the SO 2  sensor. A sample tray  122  that includes a resistive heating element  140  is located at the bottom of the testing chamber  130 . 
   The testing portion  128  is used to test a sample of the diesel fuel. Only a small sample, such as 2-10 drops of the diesel fuel is needed. The sample can be collected from any sized liquid dropper. The SO 2  sensor can be any sensor that can measure the vapor or gas of the tested diesel fuel to determine if it is within the 15 p.p.m. required by the EPA. The sensitivity of the sensor can be from about 5 p.p.m. to about 50 p.p.m. or any other sensitivity level can be used by the user so long it is within the desired testing range. 
   The door  120  is used to contain the vapor gas until it escapes from the vent holes  118 . The door  120  can include a handle (not shown) and hinges (not shown) for easy opening and closing. The door  120  can be made from any material including polymers, metals or alloys so long as they do not react with the SO 2  or the diesel fuel being tested. Although shown as triangular in shape, the vent holes  118  can be any shape including circular, rectangular, oval, elliptical, and a combination thereof. The size of the vent holes can be any size so long as they allow a detectable amount of vapor to reach the sensor. The holes can range, for example, from 1 mm to 50 mm. However, other larger or smaller sizes are also contemplated by the invention. 
   The sample tray  122  can be made from any material so long as it can be heated to a temperature that exceeds the flash point/boiling point of any diesel fuel that is tested. The heating time can range, for example, from about 2 seconds to about 45 seconds. The heating time can be lower or higher than the forementioned times due to various types of diesel fuel that can be tested. 
   The diesel fuel needs to be vaporized so that it mixes with the  02  in the surrounding atmosphere to form SO 2  that the sensor can detect and quantify. The sample tray  122  includes a heating element such as a resistive heating element made from Nichrome. The heating element is used to heat the diesel fuel in the sample tray to the boiling point. The heating element can be integral or separated from the heating tray. 
   An air pump is used to circulate the air in the testing chamber  130  so that the SO 2  sample can reach the SO 2  sensor for an accurate reading. The air pump can be any capacity pump so long as it can adequately circulate the air within the testing portion of the tester. 
   Within the housing a storage compartment  124  is provided and contains a cleaning tray  126 . The cleaning tray includes alcohol wipes and cleaning cloth. Other wipes and cleaning supplies are within the spirit of the invention. The wipes are used to clean the sample tray and the cleaning cloth is used to dry and remove any remaining residue on the sample tray. The wipes and the cleaning cloth should be the kinds that do not leave any residue, felt or otherwise contaminate the sample tray. 
     FIG. 2  is block diagram of the components of the tester  100 . A processor  202  or CPU (central processing unit) is provided to operate the tester  100 . In alternative embodiments, the processor can be an FPGA (Field Programmable Gate Array) or other controllers known in the art. The processor  202  communicates with the power switch  132 , the power source  136 , the sensor  116 , the LCD  112 , and the pump  114 . The processor includes volatile memory (RAM) and non-volatile memory  206  to store programming that operates the tester  100 . The CPU can have an external clock  208  or an internal clock. As stated above, the processor can allow communication between the components in order for the tests to be conducted by the tester and the results displayed on the LCD. 
     FIG. 3  illustrates the steps of the operation of the tester of the present invention. At step  302 , a sample of the diesel fuel to be tested is obtained. The sample can be obtained in a dropper known in art. At step  304 , the door is opened and the sample is deposited on the sample tray. The sample can be a few drops in amount from the dropper. The door is closed so the test can be conducted. At step  306 , the tester is turned on via the power switch  132 , which activates the heating element and the air pump. The LCD can also display “Place Sample” and “Press Start” in order to instruct the user. At step  308 , the sample is heated for about 30 seconds or so to its vaporized form. The heating time can be more or less than 30 seconds depending on the type of diesel fuel being tested. The LCD can display “Test In Progress,” to let the user know that the test has begun. The pump helps to circulate the air and helps the vapor to exit the testing chamber through the vent holes in the door. 
   At step  310 , the sensor takes a reading of the sample. As the vapor passes the sensor, the sensor senses the amount of SO 2  present. At step  312 , the sensor outputs the reading to the LCD. The LCD can display on one line, the sample letter, for example, “Diesel Sample A,” and on a second line, the sulfur content, for example, “23 p.p.m. sulfur content.” If a reading can not determined accurately, high or low sulfur content can be shown on the display or on another indicator such as an LED (not shown, red for high sulfur and green for low sulfur). The high or low indicator can be based on a 30 p.p.m. cutoff range, wherein below 30 p.p.m., the tester will indicate low sulfur and above 30 p.p.m. the tester will indicate high sulfur. In the mean time, the pump still circulates the air for an additional 30 seconds or so after the diesel fuel vaporized to evacuate any remaining vapors from the testing chamber. 
   In other embodiments, additional steps include step  314 , where the user power downs the tester  100  via the power switch  132 . At step  316 , the user can clean the testing chamber and the sample tray with the wipe and cloth stored in the cleaning tray. After cleaning, the tester is ready to run the next sample. 
   The tester  100  is designed to be portable so that it can be used in the field. A relatively small sample is needed and the results can be determined in the field. 
   The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.