DUI Defence in Canada: wet-bath simulator alcohol standard

In Canada we generally conduct control tests using wet bath simulators such as the Guth 2100, Guth 34C, Guth 10-4D, and Drager Mark IIA to hold and maintain the temperature of a 500 ml alcohol standard at or close to 34 degrees C. The target value of the solution used is generally 100 mg / 100 mls although other solutions are sometimes used by maintenance personnel for calibration and calibration check purposes. Other jurisdictions may use dry gas alcohol standards or the Internal Test Procedure (ITP) for control checks. We may use dry gas in Ontario in the future. ITPs are checked on every stand-alone or automatic 8000C diagnostics check in Ontario, but are not discussed in this course.

Au Canada, nous effectuons généralement des tests de contrôle en utilisant des simulateurs hydro-alcooliques, tels que le Guth 2100, Guth 34C, Guth 10-4D ou le Drager Mark IIA, afin d’assurer que la température de la solution d’alcool-type de 500 ml soit maintenue à ou près de 34 degrés Celsius. La valeur cible de la solution utilisée est généralement de 100mg / 100 ml, bien que le personnel de maintenance utilise parfois d’autres solutions pour effectuer l’étalonnage et la vérification de l’étalonnage. Cette vidéo se veut une explication générale de simulateurs hydro-alcooliques.

version française Alexandre Lafrenière

This quiz is a bit tricky. Don't worry if you don't get the "right" answer. This quiz is designed to make you think about the difference in science in moving from a known to finding out something about an unknown; not the other way around. Too often in Ontario we hear QTs tell us that bad cal. checks mean that something is wrong with the simulator or the tubing rather than the AI. Too often in Ontario we hear Crowns argue that two subject tests with 02 agreement prove everything was working wonderfully even though the QT wasn't using the alcohol standard properly in the first place. You need a reliable simulator used properly to have a reliable alcohol standard pumped into the AI, it's a condition precedent.

A Wet-Bath Simulator is the jar that holds the liquid alcohol standard. The police buy the alcohol standard in 500 ml plastic bottles. The contents of the bottle are poured into the jar. The upper metal housing is screwed to the top of the jar to make a tight seal. The contents are stirred by a propellor that evenly distributes the temperature. The contents are heated to 34 C by an internal heater and kept at that temperature by a thermostat / thermistor. Air is bubbled through the simulator during a calibration check of the approved instrument.

By now you should have some idea of the differences among simulators. Which one uses which thermometer?

While answering this Quiz you should start thinking about a number of questions:

Is it safe to assume that a digital thermometer is more accurate and precise than an old-fashioned mercury thermometer?

If a display or printout displays accuracy and precision to two decimal places does that mean that the last decimal place is reliable?

How do police make sure that their digital thermometers correspond to their mercury thermometers?

An astute defence lawyer needs to pay attention to the service interval, the maintenance documentation, the calibration documentation, and the traceability of various components of the alcohol standard / simulator system. If the function of the wet-bath simulator is to reliably hold the alcohol standard at a very specific temperature then an analysis of function v. malfunction of the alcohol standard / simulator system includes a careful examination of disclosure and cross-examination respecting both the simulator and its thermometer or thermometers.

Now that you know the basic parts of a Guth simulator, think about which items will need to be "calibrated"? Temperature stability is important so it would appear that the system that maintains the temperature at 34.0 +/- .05 C may require adjustment and calibration at regular service intervals. The digital thermometer shouldn't be expected to reliable unless it is checked against a higher precision thermometer, adjusted, and calibrated at regular service intervals. If police are relying on the RS232 electronic thermometer, then it needs to be checked against a higher precision thermometer (not just against the digital or mercury thermometer in the jar), adjusted, and calibrated at regular intervals. If your local police are using a mercury thermometer, for whatever purpose, you need to know its serial number, history of repairs of mercury separation, traceability to NIST, and service intervals. What exactly is the purpose of the NIST mercury thermometer owned by your local detachment? What are its limitations in terms of accuracy, precision, and reliability? Are local police using it beyond its capability?

When preparing cross-examination of the alcohol standard change QT, consider their methodology in emptying the old solution.

When preparing for cross-examination of the alcohol standard QT, consider their methodology in rinsing the simulator jar, opening the new bottle, and re-connecting the jar.

Your local police service probably doesn't bother to rinse the simulator jar with distilled water after dumping the previous contents. But please think about what that means. If the simulator jar previously contained an unknown substance and water, how can the new contents poured into the jar be expected to be pure after a few days of sittting in the jar? Let's suppose there was Vodka previously in the jar. Couldn't you expect some small amounts of Vodka ethanol to still be in the jar after you dumped it, thus changing the concentration when new contents ? What if the local police service had just been doing a re-calibration of the optical bench of the 8000C (which they shouldn't do) and had been using 300 solution or acetone solution in that same simulator jar?

How does your local police service flag, document, and replace chipped and cracked simulator jars?

Improper connection of the wet-bath simulator to the approved instrument can damage the sample chamber.

Please think about just how easy it is to accidentally connect the simulator outlet to the Intoxilyzer outlet. If you are using quick connectors attached to the simulator that are both female or you are pushing plastic Tygon tube onto both simulator posts you could easily switch the connections and flood the Intoxilyzer.

This video provides a demonstration of the connection of a wet-bath simulator to an ASD such as the Alcotest 7410 in non-recirculating (open) mode.

If a police service maintains proper alcohol standard logs and ASD calibration logs with outgoing seal numbers, incoming seal numbers, and anecdotal information, it is possible to identify patterns of simulator solution behaviour by individual police officers and by the detachment. Small detachments may only possess one simulator and may use that one simulator for both their approved instrument and ASD calibrations or accuracy checks.

Defence lawyers need to know and have the published maximums for alcohol standard usage at their fingertips for purposes of cross-examination. You will find these maximums in the ATC Recommendations and the CFS Training Aids.

A defence lawyer should be curious about the methodology used by their local police service in inspecting the accuracy and precision of simulators and simulator thermometers. Some police services have good protocols respecting simulator service intervals. Others have no quality assurance systems in place. If the analysis of BAC is a measurement with a range of uncertainty, then the extent of that range depends to some extent on the range of uncertainty of measurement for the simulator, the simulator thermometer(s), and the alcohol standard.

Did you know that even a new NIST mercury thermometer can be inaccurate by one or two degrees C as the result of mercury separation during shipping? Mercury can separate and collect at the upper bulb reservoir. Mercury can split into two or more parts in the lower reservoir. Daily inspection of the NIST traceable mercury thermometer is a must.

In Ontario, the "qualified technician" (QT) is expected to run three stand-alone quality assurance (QA) checks at start of shift or at least prior to the first subject test. This lecture provides a simulation of an Esc Esc C stand-alone cal. check using a Guth wet-bath simulator containing alcohol standard. The simulated screen displayed is that of an Intoxilyzer 8000C.

A defence lawyer who is preparing for cross-examination of the Qualified technician (QT), needs to know the nuts-and-bolts of stand-alone Quality Assurance (QA) checks at start of shift: how to run each one, what the QT is looking for, and possible methods of hiding unsuccessful QA checks through destruction or non-retention of embarrassing evidence.

Defence lawyers should always be careful to watch for back-dated documents generated by approved instruments. Of course, police officers should never deliberately generate back-dated documents on an approved instrument. However, if COBRA data is not downloaded and stored on a regular basis and then disclosed, it would be a simple matter for a dishonest policer officer to produce a passed diagnostic, or a passed cal. check, or a passed self-test for any date and time. In this video example, the operator back-dates the Intoxilyzer from the true date of November 15, 2006 at 10:45 a.m. to a false date of October 13, 2006 at 9:30 a.m.. The operator then generates a stand-alone cal. check which automatically produces as test record card showing a passed stand-alone calibration check at 9:32 a.m. on October 13, 2006.

Defence lawyers need to be vigilant to watch for examples of date and time changes on an Intoxilyzer. Such Esc Esc E sequences may be appropriate at start of shift or prior to the subject tests. However, Esc Esc E sequences can be abused.