Figure 1. Extracts from a Lifeloc Technologies Instrument QAP, (for illustration only)
Calibrations 1. Must be performed by a certified Calibration Technician.
2. Must be done every 12 months or when the instrument fails two consecutive calibration checks.
3. Must be followed by a calibration check.
4. Must use the most common alcohol standards for calibration including but not limited to .040, .080, and .100 BAC.
Calibration Checks 1. Must utilize Dry Gas or a Wet Bath method.
2. Must be conducted at least once every 30 days.
3. Must be performed as soon as conveniently possible after a positive alcohol test.
4. Must be performed if the unit has undergone repair.
Another Good Reason to Calibrate Calibration also provides insight into the
condition of the electro-chemical fuel cell sensing system in the instrument. Fuel cell sensitivity, response to breath alcohol, and output, can degrade slowly over time. Con- taminants such as cigarete smoke, dust, and dirt may contribute to sensor changes over long usage. Calibration adjusts the instrument read-
ings to account for changes due to these factors. Calibration problems also signal that
your unit is in need of manufacturer’s service. Good manufacturers are fully equipped to support prompt instrument diagnosis, repair or replacement of critical components to keep your units functioning to specification for many years. Recogniz- ing that an EBT is critical to your opera- tions, some manufacturers also provide free rental units to keep you going during factory service.
The Calibration Process Instrument calibration is a critical
operation in most analytical processes. Te quality of the test data is oſten directly related to the quality of the calibration standards used. For this reason the DOT maintains a Conforming Products List of Calibrating Units for Breath Alcohol Testers which lists approved manufacturers and products for the calibration and calibration check of DOT approved instruments that measure breath alcohol. Ensure that your calibration equipment and standards ultimately originate from one of these providers. Te list of conforming BAC units and calibration instruments can be found here: htp://
www.dot.gov/ sites/
dot.dev/files/docs/20121022_CPL_ Calibrating_Units.pdf Tere are two methods of calibrating a
handheld EBT, the Wet Bath and the Dry Gas2
method. Each method requires spe- cialized equipment and trained technicians. 18 datia focus
Te Wet Bath method utilizes an alco-
hol/water standard in a precise alcohol concentration, contained and delivered in specialized simulator equipment. Wet bath apparatus has a higher initial cost than Dry Gas, requires a live power source, and is not intended to be portable. Te alcohol/water standard must be fresh and replaced regularly. Te Wet Bath method is more widely used by law enforcement than in workplace testing, and is therefore not covered in this article. Te Dry Gas method utilizes a gas
regulator and a portable National Institute of Standards and Technology (NIST) trace- able calibration standard, which is a precise mixture of ethanol and inert nitrogen in a pressurized canister. Initial equipment costs are less than with wet bath and the steps re- quired are fewer. Dry Gas calibration equip- ment is very portable allowing calibrations to be done when and where required.
Who Can Perform Equipment Calibrations?
Calibrating Evidential Breath Testing
instruments is not a procedure that can be conducted by untrained users. Only properly qualified individuals called “Cali- bration Technicians” may perform EBT calibrations. A calibration performed by an unqualified technician may be considered invalid causing an entire testing program to be called into question. Te U.S. Department of Transportation
(DOT) requires that an individual who conducts valid breath alcohol testing undergo “Breath Alcohol Technician” (BAT) qualifica- tion. While BAT qualification includes the fundamentals of proficiency on the instru- ment being used, it is a common misconcep- tion that BAT training authorizes the BAT to perform equipment calibrations. It does not.
EBT calibration qualification is distinct from BAT proficiency qualification.
For the convenience of students and in- structors, Calibration Technician qualifica-
spring 2013
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