Heater Response Time on Guth 2100
Updated: Sep 27, 2022
To further challenge the Crown's suggestion that the anomalous low cal. checks that occurred in this breath truck were not caused by a door opening from time to time in winter.
To support the O'Connor application for production of contemporaneous documentation by the QT who obtained the group of low cal. checks. Documentation would shed light on possible causes of the low cal checks, any troubleshooting attempted, and the likelihood that their cause was a problem with Intoxilyzer precision.
From Guth 2100 online advertising:
Q. Now, just a little bit more about the Guth 2100 Simulator. Do you know what the manufacturer’s specification is for response time under the 2100? In other words, when the Guth simulator is used, how quickly does it – or when the temperature drops inside the simulator, inside the jar, when the temperature drops below where it’s supposed to be, how quickly it recovers? A. I don’t have that information. Q. I’m just going to show you... A. All I know is... Q. ...some material. A. ...that it would – it would come on as necessary and shut off as required in order to maintain that temperature. How long it stays, and how quickly it responds, I don’t know. Q. I want to suggest to you that the manufacturer, Guth, advertises that once it’s warmed up, warm up time less than 10 minutes, down at the bottom left, recovery time for a test is less than two seconds. A. That’s what it says. Q. So, my suggestion to you then is, that if
we are trying to, a lot of months after the events, not troubleshoot, but rather try and piece together what happened and why there were these groups of low cal-checks, it’s important to know that if there was a good simulator that had been properly.... A. Sorry, did you say good or Guth? Q. I’m sorry, good. A. Okay, sorry. Q. A good simulator manufactured by Guth, that has this specification of 34.00 plus or minus .05 that we expect was being used at 34.0 plus or minus .2, and if we’ve got data on the – the actual temperatures, from either a readout on the simulator or from a mercury thermometer in the simulator then it seems to me that if we have data points that don’t make sense, we need more information about the human component of the process to try and make sense of those data points that seem unusual and drive the standard deviation well beyond 3 milligrams per 100 mils. A. I apologise. That was rather long and you lost me. Q. Sorry. A. If you could shorten that or.... Q. When you were being asked questions by my friend, the assistant Crown attorney, and he was asking for you – for the simplest cause of the low cal-checks, and I was objecting and saying let’s talk about possible causes instead, the answers that were coming from you all seemed to relate to the simulator and I want to suggest to you, that we’ve got no indication in the case before us in the inspection reports or in our knowledge of how these simulators work to think that there was something wrong with the simulator. So, I want to suggest to you that perhaps the cause of those low cal-checks
was human error if not precision in the instrument. A. There – and I don’t remember all the reasons, or the possible reasons that I gave with respect to what can affect a calibration check result from a wet bath simulator. One of them is the temperature of the simulator. And that would probably be the least likely and – because the – this – the job of this device is that it maintains that temperature and it does it very, very well, right? I don’t think there’s any argument from anybody that that’s exactly what it does. So, that’s one possible cause, right? And again, that is affected by Henry’s Law, so for every one degree Celsius change in temperature, you get a six and a half percent change in the possible reading, right?
Q. Yes. A. Now this – as we saw from some of the numbers I was reading out, the temperature fluctuating anywhere between I think, 33.99 was the lowest, up to 34.02. Q. Yes. A. Which isn’t significant enough to have any significant change in the actual result it would produce, if you were to do a calibration check at that temperature. Q. Yes. A. However, the concentration of the solution is another variable. Q. Yes. A. How many calibration checks have been performed on that? Because you do lose, even though it’s in recirculation mode, so in other words, when you do a calibration check, Your Honour, what happens is, is that the headspace or the air above the liquid in the simulator is recirculated through the instrument. It’s not the liquid that’s circulated. That’s providing the alcohol in the air,
which is mimicking what’s happening in the body, with respect to the blood and breath. And so, that headspace, or that air, is circulated through the instrument, and every time that’s done, a small amount of alcohol is lost. And so, after you’ve done 2 or 300 calibration checks, you would lose a more significant amount of alcohol but of course, there’s a limit with respect to the number that you could do. Q. Yes. A. In this case, of 50, right? Whether it’s stand alone or as part of a subject test. So, you can lose a small amount of alcohol, which could have a contribution to the results of later calibration checks being lower, and of course, the temperature of the simulator itself, is going to be the minimum component, but the external temperature can have an effect on that. Right? With respect to, as I mentioned, that phenomenon, with that case from [another jurisdiction], is that often even though the liquid is at 34.0 degrees Celsius, right, that headspace may not be. In which case, when you do a calibration check you get a low result that’ll be outside the low end of the accepted range, which is what we’ve seen. Right? And so sometimes officers – and we teach them this, is that sometimes you’re going to have to do more than one stand alone calibration check to get that – that result to be within the acceptable range. Q. More than one. A. Possibly, yes. Q. Not many, many cal-checks where you just keep trying until you get the one that you want. A. Well.... Q. There’s a difference between there being one cal-check with maybe some cold headspace or cold tubing. That’s a lot different from running multiple cal-checks to try
and force the results into what you want them to be. A. Well, there may be a number of factors. Again, we don’t know what happened in those cases. Right? Just by looking at the data alone. Whether after one calibration check they just decided to let it warm up, after running that first one. Q. Yes. A. They let it warm up some more, so that the headspace becomes at the proper temperature of 34 degrees Celsius as well as the liquid. There can be issues with the hoses and the tubing that can be cooled, that can cause the result. I think I also mentioned the fact that if the alignment of the simulator with the Intoxilyzer is not perfectly straight and the hose becomes kinked or pinched at an angle, that can reduce the result that can be obtained as well, because then there’s less alcohol standard vapour circulating through the instrument. That can also cause that. The instrument itself, the analytical variability associated with the instrument that we know about, plus or minus 3 percent or less, the – as I mentioned previously today, I believe it was, that the pump inside the Intoxilyzer 8000C is not as strong as the one that was in the Intoxilyzer 5000C and as I mentioned, and we see here, historically we always see averages, and I’ve got data from police services up north and around the province, where when we look at the calibration check results and we do exactly what we did today, with the – let’s get the average, and do a standard deviation, is that it’s always less than 100, the expected result. Simply because of the weakness of that pump. Right? Q. So, to get.... A. It’s a known phenomenon. Q. To get to the bottom....
A. So, all – sorry – all of those together can contribute to the result being lower than expected. Q. So.... A. And there may be a few I’ve forgotten to mention. Q. So, for Mr. Kupferschmidt to say that he’s got to get to the bottom of these anomalies, before he can give a scientific opinion about what they are, that makes sense. You’ve got to get to – you’ve got to figure out what the possible causes were, and exclude possible causes of error that might be, say, human error. Might be a tubing problem, an improper installation. Maybe using the simulator in ambient conditions that aren’t proper. Before you can use this information and perform and give a scientific opinion that maybe to Mr. Kupferschmidt enables him to calculate precision and to you says we can’t calculate precision, for the reasons you’ve said, the point is, that it makes sense to investigate what these officers were doing in the period of time for which we’re looking and trying to calculate precision because it could be that the cause is human error, so we have to exclude that as a possibility. Right? A. I’m not sure that you could get that information from going back and looking at historical data. Q. No, I’m not saying going back and looking at historical data. I’m saying that when we have anomalies that appear in the historical data, and we’re trying to understand what the possible causes of those anomalies are, and whether they’re significant or not, then the most obvious request then, should be, to check the documentation that went with that event to see if the issue was human error, and if indeed troubleshooting was attempted, if there was a problem with troubleshooting, and whether or not the error was
corrected, and if that’s what caused the solution to the problem. Right? A. I disagree with that opinion, and I’ve said my – I’ve offered my opinion before, that what happened at the time of those low calibration checks is of no use in determining the proper working order of this instrument at this time, and there’s no way to take that information and use it to collect and do statistical analysis on it, or take any scientific method and say what the effect of that was on the tests in question. It’s just – simply can’t be done because it doesn’t exist. The science doesn’t exist, the statistics, mathematical formulas, that doesn’t exist to be able to take information from another time and apply it to the tests in question and or what the magnitude of that impact would be. Q. All right. A. So, it’s a – it’s a great exercise as far as, you know, that, but it’s not useful or helpful at all, for determining the proper working order of the instrument in this case.
[See also Use of Guth 2100 Wet-bath Simulator in Cold Temperatures]
See also "Know the Simulator Probes"
#crossex #probe #accessoryequipment #manufacturersspecifications
#coldweather #ambienttemperature #simulator #wetbath #responsetime #pumpin8000Cnotasstrong