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  • Stephen Biss

Calibration v. Calibration Checks


Tip 26: Do you understand the differences among these #duisimulator concepts?

1. Calibration Check

2. Inspection

3. Calibration

A "Cal. Check" or "Calibration Check" is a verification check or accuracy check of a breath measuring instrument or device. Police do verification checks of approved screening devices on a regular basis and cal. checks of approved instruments at start of shift and with every breath test to confirm that the devices or instruments are within 5 mg/100mls of expected target value or 100 mg/100 mls of expected value. This is a procedure done locally IN THE FIELD, at a police detachment.

An "Inspection" is a verification or accuracy check by a Senior Qualified Technician every six months or annually. The Inspector may use alcohol standards of 50, 100, and 300 mg/100 mls rather than just the usual 100 mg/100 mls. The OPP have trained a number of Inspectors who bring specialized simulators and temperature probes to local detachments to perform the inspections.

A "Calibration" is a (screwdriver or software) adjustment, checking, re-adjustment, checking again (as many times as it takes) in a Calibration Laboratory at the Canadian Authorized Service Centre or the manufacturer. It must be done in accordance with Canada's treaty obligations respecting fair weights and measures - ISO17025. Please refer to a text on the field of "metrology" for more information on this subject. Below please see an image of some of the potentiometers that can be "tweaked" with a screwdriver to re-calibrate an Intoxilyzer 5000. Re-calibration of an 8000C is performed using software commands that cause the instrument to re-learn values in a password-protected area of software. With both the 5000C or 8000C the re-calibration is performed using multiple wet-bath simulators containing traceable alcohol and other standards.

The Alcohol Test Committee speaks of Calibration Checks, Inspections, and Calibrations in its Recommended Standards, Operational Procedures, and Best Practices. See ATC documents.

Calibration and/or calibration check procedures are "the primary means of assuring accuracy":

Inspection is required when a new instrument or accessory equipment goes into service an PERIODICALLY THEREAFTER:

Please note that an Inspection of an approved instrument or a simulator is not a "Calibration" unless it is done at the Canadian Authorized Service Centre or at the manufacturer in accordance with strict protocols using traceable standards in a Calibration Laboratory. The CFS is not a "Calibration Laboratory" and as such, is not accredited in the area of Breath Alcohol Instrument Calibration. According to a letter from Anthony Tessarolo, Director of the CFS, dated November 12, 2012, "Instrument manufacturers, such as CMI, are responsible for instrument calibration." A police officer should therefore not be conducting a "Calibration" of an approved instrument or a simulator. A police officer, however, may re-calibrate an approved screening device. An approved instrument is a very different "kind" of instrument than a screening device because it is used for reliable evidentiary breath testing with special "approved instrument" presumptions under Criminal Code section 258. A simulator is a key item of "accessory equipment", as essential to approved instrument reliability as the alcohol standard itself. A simulator should only be "calibrated" at the Canadian Authorized Service Centre or the manufacturer, not by police. Police and police Inspectors, however, should regularly check the calibration of their simulators using reliable simulator thermometers.

COBRA data between "calibrations" is useful to the defence in identifying problems with the performance of an approved instrument or simulator. The "calibration curve" of any instrument may drift over time. A calibration check at one target value of 100 (what police in their detachments do) does not verify the whole calibration curve. To some extent an annual Inspection provides some verification of a greater area of the calibration curve (eg. between 50 and 300 mg/100mls) but it is not as complete as a Calibration in a Calibration Laboratory.

#calibration #tip

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