NHTSA and DOT outline in great detail their calibration procedure

“3.1 TEST PROCEDURE (ORIGINAL, WET-BATH CALIBRATING UNITS)
Equipment and Supplies: Gas Chromatograph capable of complete resolution of ethanol in test samples, with heated gas sampling valve. Water bath thermostated at 34 °C ± 0.1 °C. Glass Reference Sample Bottles (300 ml capacity or greater) with Stopper and Inlet and Outlet Air Hoses (see Figure 1). Hoses should be about 1/8” OD Teflon tubing. Reference Ethanol Solutions prepared using Class A glassware and American Chemical Society reagent grade ethanol or USP grade ethanol. The purity of the ethanol used shall be compared with the National Institute of standards and Technology (NIST) Standard Reference Material for ethanol. Use the value of Harger, et al., for the partition ratio for concentration of ethanol in headspace to concentration in solution at 34 °C, Ka/w = 0.000393 [4] to prepare two solutions which, when thermostated at 34 °C, produce headspace ethanol vapor concentrations that bracket the test BrAC by no more than ± 20%. Small Air Pump for bubbling air through reference solutions (see Figure 1).

Step 1. Prepare the Gas Chromatograph for measurement of vapor samples. Adjust instrument temperatures, gas flows, detector, and recording device for optimum response for ethanol. Prepare the CU for use according to manufacturer’s instructions.

Step 2. Fill two reference solution bottles to 3/4 full with above reference solutions. Insert stopper assemblies with bubble line and alcohol vapor line in place and put bottles in the water bath with water level up to the stopper. Connect air pump to bubble line. Connect alcohol vapor line to gas chromatograph sampling valve inlet fitting. Allow 1 hour for temperature equilibrium to be achieved.

Step 3. Turn on air pump which has been pre-set to pump air through the reference solution bottle-gas chromatograph sampling assembly at a rate just sufficient to thoroughly flush the system in 10 seconds. After flushing is complete, allow the sample to relax to atmospheric pressure, then inject the reference sample onto the gas chromatograph column. In this way, obtain 5 chromatograms of one of the reference solution headspace ethanol vapors.

Step 4. Thoroughly flush the sample loop with vapors from the CU device, while avoiding over-pressurizing of the sampling system. To prevent condensation of alcohol, warm the transfer line if necessary. Allow the sample to relax to atmospheric pressure, then inject the sample onto the column. In this way, obtain 10 ethanol chromatograms using the CU device.

Step 5. Repeat step 3 using the second reference solution.

Step 6. Calculations. Peak height to BrAC conversion factor. For each ethanol peak obtained in Step 3 and Step 5, calculate a conversion factor for ethanol concentration by dividing the equivalent BrAC of the vapor sample by the peak height obtained for that sample. From the 10 samples, obtain the mean and the RSD of the conversion factors. If the RSD obtained fails to meet the criteria for RSD in 3.0, perform necessary troubleshooting and repeat the procedure from Step 1. Use the mean of the conversion factors to calculate the BrAC for each of the 10 ethanol peaks obtained in Step 4. Calculate the mean, the RSD, and the systematic error of the experimental BrACs.”

Full documents available here:
https://www.federalregister.gov/documents/2007/06/25/07-3060/highway-safety-programs-model-specifications-for-calibrating-units-for-breath-alcohol-testers

https://www.fmcsa.dot.gov/sites/fmcsa.dot.gov/files/docs/Implementation_Guidelines_for_Alcohol_and_Drug_Regulations_508CLN.pdf

Police get new tool to convict drunk drivers

“Greater Sudbury Police received a new tool Monday to help convict people who drink and drive.

Action Sudbury, a non-profit organization created to eliminate the tragedies caused by impaired drivers in Greater Sudbury and surrounding area, donated a state-of-the-art calibration device to police that will ensure readings from their intoxilyzers – a machine that measures blood alcohol levels – can stand up in court.

The 12V500 Duplex Alcohol Simulator retails for $1,359 and delivers a known and precise amount of alcohol to the analyzer before each breath test.

That process lets police know the machine is working properly, said Greater Sudbury Police Const. John Coluzzi, and ensures any blood-alcohol readings it takes are as precise as possible.

With the new unit, Coluzzi said the Greater Sudbury Police Service now has five calibration devices it uses for its two intoxilyzers and the handheld devices police officers use to take breath samples when they’re out on patrol.

In addition to its pricey gift to police, Action Sudbury also presented a $1,000 cheque to Kim and Dean Hancock, the parents of DJ Hancock.

DJ, a hockey player with the Sudbury Nickel Capital Wolves, was killed by a drunk driver Aug. 21, 2014, while driving on Highway 17.

The Hancocks will put the donation toward a splash pad they hope to build in DJ’s honour.
“I think it’s awesome. Action Sudbury are doing as much as they can for the drinking and driving campaign,” said DJ’s mother Kim.

The splash pad is expected to cost around $225,000 to build. Kim said they are around $40,000 away from having the funds necessary to begin construction.
She added if all goes well, they should break ground for the splash pad in the spring.”

Original article published at:
https://www.sudbury.com/local-news/police-get-new-tool-to-convict-drunk-drivers-257731

With the rise of personal breathalyzer use, calibration of more accurate breath tests still critically important

“We have encountered students who have used [personal breathalyzers] thinking they were sober, trying to be responsible, and getting a DUI shortly thereafter,” Letendre said.”

Letendre says not all personal breathalyzers are as accurate as the readings we found in our test with BackTrack and warns about a ‘false sense of security’ for drivers who use them.

“Under .08 or .05 doesn’t mean you are sober,” Letendre said. “To say that this portable breathalyzer is telling me ‘yes,’ I have alcohol in my system’ I know there’s alcohol in my system, I don’t need to blow into a machine, and we say in our classes, ‘if you’ve had a drink, just don’t drive.”

Full article here:

https://abc3340.com/news/nation-world/can-you-trust-a-smartphone-breathalyzer-to-tell-you-if-are-sober-enough-to-drive-02-04-2019