The AS IV is a handheld alcohol screening device. It has a small display for messages, prompts, and readings. It provides numerical readings when the BAC is between 0 – 59 mg%, WARN messages when in the range of 60 – 99 mg%, or FAIL messages for 100 mg% or more. In order for the test results to be reliable the device must be operated and calibrated correctly. Immediate roadside prohibitions (IRPs)may be given to drivers that get a WARN or FAIL message.
The AS IV is based on fuel cell technology.
When a person drinks alcohol, it is absorbed into their blood and then passes into their breath. If the breath sample is captured by the AS IV fuel cell, an electrical current will be created that can be measured. The higher the current, the higher the amount of alcohol in the blood.
Here is the sequence of events when a police officer takes a breath sample from a driver on the AS IV device:
1. The police officer must commence a test sequence on the AS IV (which includes a temperature check and other instrumental self-checks) before the device displays TEST and is ready to take a breath sample.
2. The driver will be asked to blow into the AS IV.
3. As the driver blows, the device can display a number of symbols and messages, such as +, ++, NoGo, VOID, or others.
4. If the flow of breath from the driver is of sufficient force and duration, the breath sample will be analyzed, and the device will display one of the following:
– a number for a BAC of less than 60mg%,
– the message WARN, for a BAC of 60 – 99 mg%
– the message FAIL, for a BAC of 100 mg% or higher.
5. If the breath sample is not of sufficient force and duration, it will not be accepted by the AS IV. The device will automatically return to “TEST” so that another breath sample can be attempted. There are up to three opportunities to blow during a single test sequence. If a breath sample is not accepted by the third attempt, the sequence ends. A new test sequence will have to be started before another breath sample can be attempted.
6. The test result will be shown to the driver because the AS IV does not produce a paper report. If the result of the breath test is a WARN or a FAIL, the officer must offer the driver a second breath test on another handheld screening device. This second test is optional to the driver.
7. The police officer will write down the results and details of the breath test. The officer will also include a brief description of the device operation, and the way in which the breath sample was, or was not, provided. These details will be recorded in the IRP narrative, as well as in the Report to Superintendent. This evidence can be very important in supporting any FAIL, WARN or Refusal IRPs. Sometimes the police officer will make an error, leave out important details, or provide confusing descriptions of device messages – leading to concerns the device was not being operated properly or was not functioning properly.
8. Not every police officer may operate the AS IV. All qualified users of the device must successfully complete a training course and must indicate in the documentation they are a qualified operator of the Alco-Sensor IV DWF.