Intoxilyzer 5000 DWI Breath Test Variance

In our last blog entry, we discussed how an Intoxilyzer 5000 has to detect a minute amount of alcohol in a breath sample without error. A Floresville criminal defense attorney must highlight the weaknesses in the machine’s accuracy.

Specifically, the test results from the machine are + / – 0.010. A test sample can be off by 0.010 under the Texas Administrative Code . We discussed that the test sample should be 0.080 but in reality, the sample can range between 0.070 and 0.090 and still be considered reliable.

The strongest cases are where the breath sample is between 0.080 and 0.089. If the accuracy rating is + / – 0.10, then the breath sample can be off by 0.010 . Thus, a breath sample was 0.087, then theoretically, the true result could very well be 0.077. Theoretically , the State can argue that the accuracy variation of + / – 0.010 means a breath result of 0.088 could be 0.098. However, that type of variation is further evidence that this machine does not possess the precision it claims.


A jury would be hard pressed to convict beyond a reasonable doubt where the breath sample is below or equal to 0.089.

In addition, the test operator must observe the arrested driver for at least fifteen (15) minutes to make sure the driver does not inadvertently belch causing stomach gas to build in the mouth . Moreover, the test operator has to make sure the temperature is proper on the test sample jar before commencing the test.

You should immediately contact an Austin DWI lawyer especially if your breath test was less than or equal to 0.089.

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