Alcohol Monitor Devices

Here is a brief description of the different types of alcohol monitor devices that are available to those who are charged with an intoxicated offense and required by the Court or Probation:


Interlock Device

man blowing into ignition interlock device

The point of an ignition interlock device is to prevent your vehicle from starting if you have alcohol on your breath. The device is a computer that is connected to your vehicle’s ignition with a breath test machine attached to it. Sometimes these devices even include a camera to identify the person providing the breath sample. If you have alcohol on your breath, you will be locked out for a certain period of time (usually one hour) before the machine allows you to re-test and attempt to start your vehicle.

An ignition interlock may detect alcohol of any kind. This means that it may be triggered by things like mouthwash leftover in your mouth or any body spray you may have used inside your vehicle. Before or during installation you are usually given information covering the do’s and don’ts of the machine.

Many Texas courts require you to install an ignition interlock on your vehicle if your blood alcohol concentration is shown to be at or over a 0.15 or you are charged with a DWI second offense, or a felony DWI. When the device is placed in your vehicle for any of the above mentioned offenses, it can be a condition of your bond while your case is pending. In most instances the ignition interlock is required to be on your vehicle if you have been convicted of a DWI.

The company who installed the machine monitors the device. Usually the monitoring is done by monthly calibrations. You must report on a monthly basis to the installer to have your ignition interlock device calibrated.

During calibration, the machine is checked to make sure it is working properly and the monthly report is taken from the machine’s computer. The monthly report shows when you started the vehicle, whether you had a breath sample positive for alcohol, and if so, how much it was able to read. If you have a positive sample, it will also record each subsequent sample to show whether or not the reading was in fact alcohol or whether it was an interferent.

For example, if there is something with alcohol in it, such as body spray, that the machine reads while you give a sample it will lock you out and require you to wait through the lock out period. However, many times, the interferent will have gone away and the recording will show that you tested clean (i.e. breath sample is a 0.16 but one hour later is a 0.00). Two consecutive readings of this kind would not indicate that you have alcohol in your system because your body cannot eliminate alcohol that quickly.

Prices to have an ignition interlock installed on your vehicle may range from $100 to $150. Monthly fees for the device range from $50 – $80. The monthly fees are usually paid when you have the device calibrated.

It is very important to have a knowledgeable attorney that is able to read the calibration report because having a positive alcohol reading on your report may result in very bad consequences. Possible consequences include having your bond conditions amended or your bond amount raised, causing you to either pay for an additional monitoring device or go to jail and post a higher bond while your case is pending. If your device reads positive while you complete probation then a judge may revoke your probation and send you to jail, or order additional probation conditions, or both.

A knowledgeable attorney can look at a report to make sure it is complete and accurate. Many times a violation will be reported to the court based on an inaccurate reading of the report. Parts of the report are not available for a judge to realize something other than alcohol caused a bad reading. It is your attorney’s job to point out these errors, if present, and otherwise advocate for you.


In-Home Device or Soberlink

portable breathalyzer device and case

Devices like Soberlink or an in-home monitoring device are portable alcohol monitoring devices. They are commonly court-ordered as an alternative to the ignition interlock for offenders who don’t drive or own vehicles. Similar to most alcohol monitoring devices in vehicles, the in-home device and the hand-held Soberlink device have cameras attached. The device reports the subject’s picture and makes it available to the monitoring authority for photo-matching.

Both devices are portable and relatively simple to use. The In-Hom device offered by Smart Start, Inc. is a 3-lb. device that must be plugged into an outlet; no phone service or internet service is necessary. Once a month, the unit is calibrated at a Smart Start, Inc. location and all test results are uploaded and sent to the monitoring authority.

The Soberlink device is a smaller, hand-held unit that requires Verizon cell phone service to upload results instantly after testing. The amount of tests required per day is determined by the monitoring authority. Monitoring authorities can change the amount of tests or the time of the tests at any time.

Both of these devices use fuel-cell technology to test breath samples for alcohol. The fuel cell within the device has two platinum electrodes with a porous acid-electrolyte material between them. As a breath sample runs through the device and passes one side of the fuel cell, the platinum oxidizes any present alcohol in the air and produces acetic acid, protons, and electrons.

The electrons flow through a wire from the platinum electrode. The more alcohol in the breath sample, the greater the electrical current. That electric current is then measured and calculates blood alcohol content (BAC). If there is no alcohol present in the breath sample, then no oxidation occurs, and the result should read 0.00.

The #1 concern with all alcohol-monitoring devices is false positives. Both Soberlink and Smart Start, Inc. recognize that certain household products can cause false positives on their devices. However, Soberlink’s site indicates that there has not been a proven household item that will cause a false positive 15-20 minutes after exposure to that item. The site lists mouthwash, toothpaste, hand sanitizer, and bug spray as items that will illicit an initial false positive but that will show a 0.00 within 15-20 minutes after exposure.


SCRAM: Secure Continuous Remote Alcohol Monitoring

SCRAM device

As a part of pending DWI or DWI probation, it is common that courts require abstinence from alcohol. To monitor a person’s alcohol consumption, there are many resources at the disposal of the court. Of all the available alcohol monitoring devices, SCRAM provides the most frequent alcohol monitoring.

Essentially SCRAM is an ankle bracelet that measures your sweat for the presence of alcohol. This is called transdermal alcohol testing. The  SCRAM device is worn 24/7. It is water-resistant, and it has safeguards to prevent tampering. The device takes a reading every 30 minutes and the information is transferred daily to a base station, which stores the data.

Transdermal devices have only been available since 2003, and the SCRAM (Secure Continuous Remote Alcohol Monitoring) device is the most common commercially available, transdermal monitor. The popularity of this device has grown tremendously since 2003, and now these devices are used in almost every state.

Even though transdermal monitors are relatively new to the market, the underlying science has been established since 1930. As a person ingests alcohol, that alcohol is diffused throughout the water in the body. After ingestion, alcohol is present throughout the body, including in your blood, breath, urine, and sweat.

While the liver metabolizes most of the alcohol consumed, about 1% of alcohol consumed passes through skin. Alcohol can pass through the skin in two forms: sensible or insensible perspiration. Sensible perspiration is sweat in its liquid phase; insensible perspiration is sweat in its vapor form. Insensible sweat is constant and unnoticeable. The average person emits about one liter of insensible perspiration per day. SCRAM works by measuring the ethanol gas in your insensible perspiration.

The SCRAM system has three components: the bracelet, the modem, and the software. The bracelet is an 8-ounce tamper- and water-resistant device. It contains a Draeger fuel cell, a computer chip to store information, and anti-tamper features. The modem communicates with the bracelet via a radio frequency signal. The software component of the SCRAM system is called SCRAMnet. It is a web-based application that stores and organizations the data received from the device.

The SCRAM bracelet has two sides. One side contains the ethanol sensor, and the other side contains the tamper-resistant technologies, including the temperature sensors and removal detection electronics. When a SCRAM device is attached to a person, a tamper clip is used. The tamper clip is a one-time use device that secures the SCRAM strap and battery.  In order to be removed, the tamper clip must be destroyed.

SCRAM also is able to detect when the battery is inserted, so authorities can see if a person removes and later reinserts the battery. In addition, the SCRAM device can tell if someone cuts the strap. A small electrical signal continuously passes through the straps, and a break in that signal is evidence of someone cutting the strap or tampering with the device.

SCRAM also contains an infrared (IR) sensor. This sensor shines a beam of infrared against the skin. The skin absorbs some of the beam, and some of the infrared beam is bounced back to the device. When initially installed, the device records a baseline IR reading. If the IR signal received varies by a great enough percentage from the baseline reading, it is considered a tamper, meaning that a foreign object was inserted between the device and the skin.

SCRAM is also equipped with a temperature sensor that monitors the temperature taken each reading. A variance in the temperature reading can be indicative of tampering (like placing an obstruction between the bracelet and one’s skin). Generally an obstruction will result in a lower temperature reading.

Once set up, SCRAM will take a reading every 30 minutes. When SCRAM detects alcohol, this detection must be monitored for three readings in order to determine if the SCRAM is registering alcohol consumption or some type of interferant (like alcohol in the air or something applied to the skin which contains alcohol). SCRAM will compare the three readings. If the person has truly consumed alcohol, the readings will not show a dramatic increase or decrease between the three readings, but rather a slow, gradual change.

In Bexar County, SCRAM will cost $360 per month or $182 every two weeks. Whether the payment is monthly or every other week, is up to the person wearing the device. In order to set up the device, a person must pay $75 + their regular payment ($360 or $182, which ever way a persons has elected to pay). Using the device also requires the person to appear every 90 days have the device refitted, and sometimes the device is switched to the other leg.

When alleged violations are reported to a monitoring agency, often times a “violation report” is generated. This report will include graphs along with other readings regarding the alleged violation. It is important to have a knowledgeable attorney who can properly evaluate these reports. Often times the reports can be difficult to interpret. If the report is misleading, it can lead to dire consequences, unless you have a competent attorney to intervene.


molecular structure of Antabuse

The molecular structure of disulfiram (i.e. Antabuse)

Antabuse, or disulfiram, is a drug discovered in the 1920s that became the first FDA-approved medicine used to treat chronic alcoholism. The substance was developed to provide a remedy for parasitic infestations; however, workers testing the substance on themselves reported severe symptoms shortly after alcohol consumption.

Today, Antabuse is prescribed to help people quit drinking by causing a negative reaction if the person drinks alcohol while taking Antabuse. Under normal conditions, alcohol is broken down in the liver by the enzyme alcohol dehydrogenase to acetaldehyde, which is then converted by the enzyme acetaldehyde dehydrogenase to harmless acetic acid.

However, taking Antabuse interferes with this metabolic process and prevents the oxidation of acetaldehyde into acetic acid. The result is some 5 to 10 minutes after alcohol consumption, the patient may experience the effects of a severe hangover for a period of 30 minutes up to several hours. Symptoms include flushing of the skin, accelerated heart rate, shortness of breath, nausea, vomiting, throbbing headache, visual disturbance, mental confusion, postural syncope (fainting), and circulatory collapse.

There is no tolerance to Antabuse; the longer it is taken, the stronger its effects become. As Antabuse is absorbed through the digestive tract and slowly eliminated by the body, the effects may last for up to two weeks. Although Antabuse does not reduce alcohol cravings, a nine-year study published in 2006 found that the incorporation of a supervised Antabuse regimen and a comprehensive treatment program resulted in an abstinence rate of over 50%. Today Antabuse is often accompanied with newer drugs such as naltrexone or acamprosate, which directly attempt to address physiological processes in the brain associated with alcohol abuse.

Only someone who wants to try to quit drinking and who is fully aware of the consequences of drinking while on the medication should take antabuse. Antabuse should never be given to some without their full knowledge or to anyone who is intoxicated. Additionally, because of the possible severe reactions, Antabuse should not be given to anyone with a history of severe heart disease, psychosis, or an allergy to Antabuse. Women who are pregnant should not take Antabuse and no one taking paraldehyde or metronidazole should use Antabuse.

The following is general information for a defendant if a Bexar County court has ordered Antabuse as a condition of bond:

The individual will be required to take the Antabuse medication in pill form three (3) times per week to deter alcohol consumption. Antabuse is taken on Monday, Wednesday, and Friday at the Bexar County Antabuse Clinic located at 230 Fredericksburg Road, San Antonio, Texas 78212.

Defendants will be medically screened and evaluated by a physician. A fee of $60.00 will be charged to the defendant as services rendered.

The Antabuse program is an offender paid program and the cost of the medication is $8.00 per pill: $24.00 per week; $96.00 per month.

The defendants will also be required to submit to random drug and alcohol testing as a stipulation of the Antabuse order. The defendant will be required to pay a $10.00 fee for each test administered.



If you have been required to wear any alcohol monitoring device by the court as a condition of your bond, it is crucial that you have an attorney who is knowledgeable in the areas of DWI defense.

Only a well-trained DWI attorney will be familiar with the limitations of these machines so that they can defend you in front of the court, if need be.

Just because you are on probation doesn’t mean you no longer need a lawyer! If an interferent causes an invalid reading that brings you back into court, you want to know that you have an advocate on your side who will defend you in court.

Call the DWI Dude today to review your case and see how we can assist you.

Leave a Reply

Your email address will not be published.