When I first speak to my clients about their San Diego DUI arrest they bring up the breath test in the field. It is mistaken for the chemical tests that are taken back at the station (unless there is a checkpoint or similar). There is a significant difference between the Preliminary Alcohol Screening (hereinafter PAS) device to the chemical tests.So what is the PAS Device in a San Diego DUI?A PAS is a device used in preliminary
breath tests to determine the blood-alcohol level of an individual.
When an officer pulls over someone they suspect have been drinking, the officer may
ask the suspected person if the officer can administer a preliminary breath test. The test is usually requested in the field sobriety phase of a San Diego DUI arrest.The PAS device is a hand-held device used in the field by officers to obtain
blood-alcohol levels of someone. However, it usually can only be an indicator that alcohol is present.There are several different PAS systems, but there are generally two main types in a San Diego DUI. These are the Fuel cell devices and/or Taguchi gas sensor devices.a. Fuel Cell DevicesFuel cell devices measure the ethanol in a person’s breath.Some problems with
this test are that the device also reacts to acetaldehyde, methanol, isopropanol, and n-
propanol, and thus the test may be tainted by these substances. Additionally,
the test reacts to temperature, and is subject to build-up which can cause a false reading.
|Thus, fuel cell devices may pose evidentiary problems. The Alco-Sensor model IV is|
|one of the more commonly used PAS devises used in California, and has a black-dot and
green-dot version.b. Taguchi Gas Sensor
The gas sensor has small elements that attract alcohol in the breath, and give a reading
WHAT IS THE DIFFERENCE BETWEEN A BLACK-DOT AND A GREEN DOT PAS?
This is an important distinction in a San Diego DUI case. It must be found out by a San Diego DUI attorney. I have seen the officer does not know which one he is using.
a. The Green一Dot PAS
The Alco-Sensor IV has both a black-dot version and a green-dot version. The
b. The Black-Dot PAS
dot system does not have. Both systems work fairly the same way, other than the
So How does a PAS work?
The fuel cell devices and the gas sensor devices work in different ways. The fuel cell
devices work by burning up the ethanol in a fuel cell, thus giving a reading of the BAC. As stated above, problems can arise when the device burns something other
The gas sensor devices work in a little different way, as they contain small elements
I can tell you that unless this area is reviewed, the jury will just take the >PAS reading as the gospel. There is a reading that there is a chemical sample back at the station. Those tests are far more reliable. It is important because these machines are determining whether someone drives home that night or will be spending time in jail.
Hire a Proactive, affordable, and quality defense when you are facing San Diego DUI charges. Whether you have been charged of a San Diego DUI, Poway DUI, La Mesa DUI, Santee DUI, Mission Valley DUI, Clairemont DUI, Point Loma DUI, La Jolla DUI, Carmel Valley DUI, Mira Mesa DUI, Pacific Beach DUI, Del Mar DUI, Carmel Valley DUI, Encinitas DUI, Oceanside DUI, Ocean Beach DUI, Escondido DUI, Vista DUI, San Marcos DUI, Carlsbad DUI, El Cajon DUI it is vital you need to hire an attorney who knows how to defend your rights and can determine if the government can prove their case. Contact the Law Office of Mark Deniz now for a free case evaluation.