close up of woman blowing into breathalyzer machine for DWI

Problems With DWI Breath Test Machines in Texas

Texas has transitioned away from the Intoxilyzer 5000 EN device and is now using the Intoxilyzer 9000 to conduct DWI breath tests. However, this change does not mean that the new machine has no faults. Let’s go over some reasons why the results of the Intoxilyzer 9000 are not always reliable.

1. Device Sensitivities

One of the main issues with the Intoxilyzer 9000 is its sensitivity to compounds other than ethanol. While it can detect ethanol in one’s breath, it may also read other chemical elements by mistake. For example, drivers with diabetes may produce acetone in their breath sample. The device can pick up on the acetone and mistakenly read it as drinking alcohol.

2. Result Variation

The Intoxilyzer 9000 device has a 20% variance rate. This means that if the two samples provided by the driver are within 20% of each other, the results would be considered accurate. However, this is a relatively high variance late. This also means that a driver’s samples could easily show them over and under the legal BAC limit.

3. Possible Interference

Some data shows that the Intoxilyzer 9000 is more susceptible to police radio interference. In other words, police radio and cell phones can affect breath test results.

General Breath Test Errors

In addition to these issues unique to the Intoxilyzer 9000, all breath test devices are vulnerable to error.

All types of breath test evidence may be unreliable due to:

  • Improper test administration
  • Police error when recording the results
  • Device malfunctions
  • Lack of calibration
  • Temperature affecting the device
  • Mouth alcohol

DWI Defense in Austin, Texas

If you have recently been arrested for driving while intoxicated in Austin, contact our defense team at Smith & Vinson Law Firm. We will look into all aspects of your stop and arrest, including any factors that could have affected your breath test results. There are numerous ways these devices could produce inaccurate results, and we will investigate all options.