Breath temperature is a critical component to any breath testing program. Breath testing, in most machines, is assumed to be at 34°C. However, you know what they say about assume? This assumption improperly inflates your client’s true BAC result. Even the police acknowledge this problem in breath testing. The IACT Newsletter, Breath Temperature: An Alabama Perspective, found here: https://drive.google.com/file/d/0BxbLCAZZvzl3cUZhczRkcUpmTnc/view?usp=sharing determined in their study that the mean breath temperature was 35.1°C, more than a degree higher than the machine assumes.
This wasn’t an abnormality, but the norm. 93% of the tests were higher than 34°C. The article also points out the Schoknecht Study, which had 700 subjects, versus the minimal amount in the other cited studies, shows a possible temperature as high as 36.7°C, or almost 3°C higher than assumed by the machine.
For each degree C the temperature is over stated, it increases the test result by 6.7% or more. A test result can overestimated by nearly 20%. Reduce your client’s result by the same 20%, and it may very well bring her below the legal limit. Another tool you can find in the virtual library
The virtual library is full of useful information. We have all the SFST manuals, and have added the 2015 update. The NHTSA SFST manual on DWI Detection and Standarized Field Sobriety Testing is one of our best tools. I have found that the way the officers are instructed to investigate a DUI case is much different than how they actually conduct the investigation in the field. The NHTSA manual lays it all out on what they should be doing.
Some of the most helpful sections are the Vehicle in Motion and Personal Observation. Both of these sections will give the practioner a fountain of informaiton on all the things the officer didn’t see, and all the reasons why your client was sober.
The Pre-Arrest Screening, also sets forth the standards of proper administration of the Field Sobriety Tests. And in the 2015 SFST Manual they placed back in the language we all loved to beat them with.
It is necessary to emphasize this validation applies only when:
If any one of the SFST elements is changed, the validity may be compromised. This was so important, they moved it up in the manual. Find it here: https://drive.google.com/file/d/0B8rbj7RPFLobdkNCLTZyemlQYVk/view?usp=sharing