What calibration actually involves
Evidentiary breath instruments are checked against reference samples with a known alcohol concentration, so the machine's readings can be compared with a standard. In New York, breath testing instruments must be of a type approved by state health authorities, and the agencies that use them keep records of maintenance, calibration checks, and repairs. The reference solutions or gas used for those checks have their own lot numbers and expiration dates. A result is only as dependable as the maintenance history behind it. When the records are complete and consistent, that is meaningful information as well.
Records worth requesting
The documents that usually matter include the instrument's calibration and maintenance logs, its repair history, the certification of the officer who ran the test, and the record of the test itself. Breath testing protocols also generally call for an observation period before the sample, so that nothing in the mouth skews the reading, and how that period was documented can become an issue. Instruments may also produce data showing error messages or repeated attempts. Entries showing the instrument was moved, repaired, or taken out of service around the date of your test deserve particular attention. We request the underlying records rather than relying on a printed result. Gaps or inconsistencies do not automatically make a result unusable, but they can affect how much weight it deserves.
What you can add from your side
Some issues come from the person rather than the machine. Recent use of mouthwash or breath spray, dental work, acid reflux, and certain medical conditions can bear on a breath reading in some situations. Tell us what you ate and drank, and roughly when, as well as you can recall, along with any health conditions or medications. Mention whether the officer stayed with you before the test and whether you burped or vomited during that time. These details help us judge whether the recorded number reflects what it claims to, alongside whatever the instrument records show.
