• Stephen Biss

Flooded Sample Chamber 8

This instrument has been left sitting idle for a long time. My hope is that all the moisture in the sample chamber has dried out. Maybe doing nothing to repair it will fix what ails it? Today, it started out again with an incredibly high DVM (see below video at 600)and then settled down to 400 (see below video). But before long: Wow! A Stand-alone Diagnostics "Pass" and a Stand-alone Self Breath Test "Pass":

Video of 11:18 Diagnostics OK

According to the CFS 8000C Training Aid of 2013, page 80 of 238, these two tests, if performed on an 8000C, establish that this instrument is "in proper working order" and is "capable of receiving a breath sample."

But what about calibration? Is the instrument capable of producing a good cal. check? Does one good cal. check prove that: "the instrument is properly calibrated". See the wording of the 2013 CFS 8000C Training Aid at page 80 of 238.

The group of cal. checks on the left were run with no simulator and no alcohol standard attached. They all indicate zero. That's good and correct - it seems to show calibration at zero with no ethyl alcohol. The group of cal. checks on the right were run using a Guth 2100 simulator with 100 solution at 34.0 C. Notice that the second cal. check on the right, viewed in isolation, shows a good result of 92 mg/100 mls, well within the acceptable range in Ontario. But notice how much the results are wandering. This instrument suffers from poor precision and its average accuracy seems to be very low of the target.

This is a video a little earlier at 12:14 with one of a group of cal. checks at 93 mg/100mls. Precision is obviously a problem. But how can you tell that looking at individual cal. checks in isolation?

Quaere: Is obtaining one or two or three good cal. checks spread out over the testing sequences, the same thing as checking the calibration of the instrument? Are stability checks at annual inspection of importance to defence lawyers?

This instrument continues to wander in its DVM. This was the DVM when initially started about 11:05.

By about 11:17 the DVM had settled down to 400 and it was time to attempt a restart.

Warning: What you read on these pages is not evidence; you cannot use these images or videos in Court. This discussion is for lawyers.

18 views0 comments