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Breath Sample Challenges

The police get a two-hour window to test you – that’s it.


Most of the people tested as a result of arrests in Clark County will be tested by personnel within The Clark County Detention Center under the policies and procedures of the Las Vegas Metropolitan Police Department. Metro’s policy on the breath instrument (The Intoxilyzer 8000) is listed below. It is both complex and extensive:


2.2 Principle Per NAC 484C.120, each evidential breath testing instrument must be calibrated at least once every 90 days. The calibration must consist of an appropriate response to no less than 3 levels of alcohol, within a range of 0.00 to 0.40 g/210L of breath. All maintenance and calibration information must be entered into a DUI Logbook (NAC 484C.140), and maintained in a laboratory record (NAC 484C.150).


2.3 Procedures

2.3.1 Calibration Procedure Calibrations must be performed at least once every 90 days or less for each instrument in service.  Utilize three or more calibrator solutions to check the readings of the instrument, three times each, through the calibration port.  Examples of approximate values: 0.04 g/210L 0.08 g/210L 0.20 g/210L 0.30 g/210L Document/record calibration and responses in the instrument’s DUI Logbook.  Record the calibration on the 90 Day Calibration Checklist.


2.3.2 Performance Checks Procedure Additional performance checks should also be completed at the time of the calibration:  Print diagnostics and check DVM values. Run reference standard once, to verify that the regulator is in working order. Check and note the lot number, expiration date, and PSI of the attached gas standard. Breath Alcohol Technical Manual Approval Date: 06/27/2018 Document Number: 5122 Approved By: Michael Stypa, Kim Murga, Darby Lanz, Cassandra Robertson Revision Number: 3 Date Published: 06/27/2018 Uncontrolled Copy if not located in Qualtrax Page 6 of 27  Simulate a breath test to ensure the instrument responds correctly to the following: Instrument automatically samples standard test.


First Subject Sample: blow an aqueous solution, with a known concentration, through the breath tube.


Second Subject Sample: blow an alcohol free air sample through the breath tube.


Refuse the third sample.


Interferent (acetone) detection (check at least once per calendar year). Use a breath alcohol simulator containing an aqueous solution prepared to simulate approximately 0.10 g/210L (section 3.3.1) with approximately 200 µL of acetone added, through the calibration port, three times.  Record the results of the simulated breath test and interferent detection in the DUI logbook, and complete the 90 Day Calibration Checklist.


 2.4 Interpretation of Results

 2.4.1 Calibration Results  The three instrument results must agree within ± 10% or 0.005 (whichever is greater) of known concentrations and all be within 0.003 g/210L of each other.


2.4.2 Performance Checks Results  Pass and print diagnostics Regulator check – should allow for gas to be sampled.  DVM values Channels 3 and 9: values fall between 9000 and 14000 S: Span (noise): < 9  C: Sample Cell Temperature: 47C + 0.2C B: Breath Hose Temperature: 45C + 2C or -9C Gas Standard  Note PSI and expiration date. Replace tank if necessary. Simulated breath test Standard test must be within ± 10% of known concentration.  Solution blown through the breath tube must be within ± 10% of known concentration. Alcohol free air must be negative for volatiles. Instrument must accept a refusal for the 3rd subject test.  Interferent Detection Instrument must detect acetone as an interferent. If these criteria are not met, attempt to determine reason using previous experience, service manual or other procedures or information gathered from other sources and/or training. In situations where accurate results Breath Alcohol Technical Manual Approval Date: 06/27/2018 Document Number: 5122 Approved By: Michael Stypa, Kim Murga, Darby Lanz, Cassandra Robertson Revision Number: 3 Date Published: 06/27/2018 Uncontrolled Copy if not located in Qualtrax Page 7 of 27 cannot be obtained, the instrument must be removed from service until repairs are made and calibration results are acceptable.


2.5 Reporting and Record Keeping  Record all maintenance and calibration results in the maintenance record in BRAD. If any portion of the calibration was repeated or failed:  the failed/repeated reason must be noted on the printout and kept with other results document repeat in the maintenance record (example: “0.04 repeated – see scans”)  If the calibration and performance checks were completed satisfactorily, prepare a Report of Calibration. Reports of Calibration will be technically and administratively reviewed prior to distribution.  Maintenance records (including scans of printouts from Intoxilyzer) and log sheets will be released only under subpoena or court order. The Report of Calibration (along with a related Report of Gas Standard (see section 4.4 Reporting and Record Keeping)) will be distributed to appropriate parties by laboratory staff. Original Reports of Calibration are maintained by the Nevada Department of Public Safety – DMV Hearings office.  Printouts, maintenance records and any notes generated from calibrations and instrument maintenance will be kept on site, or in a digital format, for a minimum of seven years. After seven years, these records may be destroyed. Breath Alcohol Technical Manual Approval Date: 06/27/2018 Document Number: 5122 Approved By: Michael Stypa, Kim Murga,


The police fail to test you within the two-hour period.


The police can allow more than 90 days to elapse between calibration tests.
They can use an expired test sample solution.
The three solution samples may not be near enough in result when they were blown through the instrument.
The police could use a gas sample that is past its expiration date.
The police could fail to properly maintain the calibration log book. In government employment there is an old saying: “If you did not document it, it did not happen”
The police are also supposed to observe you for 15 minutes straight after you are arrested to make sure you do not drink alcohol, burp or vomit – since those things may result in an abnormally-high reading. This occurs due to alcohol from your stomach coming up into your mouth. If the police failed to notice that you burped or threw up – it may convince the District Attorney, judge or jury to not give much weight to your breath results – since they would be contaminated.
You had a health problem that the police failed to ask you about and it skewed the results i.e. Heartburn, Acid Reflux etc.
Local radio waves interfered with the ability of the machine to operate properly.
The Breath Test Operator was not properly certified and/or his or her certification had expired.
Things you ate were metabolized in your body and produced abnormally-high breath alcohol, creating the false appearance of impairment.


Any of these simple mistakes can cause your breath sample to be suppressed. The suppression of that sample could convince the District Attorney’s Office to make you a more favorable offer, or cause a jury to decide that the evidence against you was lacking enough as to constitute reasonable doubt.

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