Bump Test
Functional Check: A qualitative function check where a challenge gas is passed over the sensor(s) at a concentration and exposure time is sufficient to activate all alarm indicators to a minimum of their lower alarm setting. The purpose of this check is not to confirm the accuracy of sensor response, just that gas can get to the sensor(s) and that all the alarms present are functional.
Accuracy Check: A quantitative function check using a known concentration of gas that is traceable to a recognized standard to confirm that the alarms are functional and that the sensor(s) response is within acceptable limits. Typically, a +/-10% to +/-20% of applied gas value is considered acceptable unless otherwise specified by the manufacturer, internal company policy, or a regulatory agency.
Calibration
Zero calibration: Establishes sensor(s) baseline reading, 20.9% oxygen and free of any toxic or combustible gas vapors. To maintain a stable baseline, it is essential to perform zero calibration in fresh air. In the event, fresh air cannot be confirmed, use zero grade air or N2 to perform a detector zero calibration. Perform a zero calibration to reestablish baseline as required, and before a span calibration.
Span calibration: The adjustment of the sensor(s) response to match the value of a known concentration of applied gas that is traceable to a recognized standard. The calibration procedure should be done in accordance with the equipment manufacturer’s instructions.
NOTE: Consult the product manual at all times for product specific recommendations.
Recommended Frequency
Fixed gas monitors:
- Perform an Accuracy Check on a 4 to 6-month basis based on region at a minimum
- Perform a Zero calibration and *Span calibration prior to first time use and then on an annual basis at a minimum
- o *Factory calibrated sensors may not require a Span calibration at first time use
- o Infrared (sealed construction only) and ultrasonic based products typically do not require span calibrations and should be avoided where possible
Direct Reading Portable Gas Monitors:
- Perform a Function or Accuracy check prior to each day’s use at a minimum.
- Perform a Zero and Span Calibration prior to first time use. Calibration frequency can vary from every 30 to 180 days, or, calibrate following a failed bump test.
Non-direct Reading Portable Gas Monitors:
- Perform a Function check periodically (at least once a week)
- Perform a Zero Calibration as required; Span Calibration is typically not required over the working life of the monitor.
Flame Detection Testing
Electro-optical flame detectors:
- Perform a lamp test on a semi-annual basis. Perform a complete fire protection system function test annually.
A copy of the original Notice can be find attached this article.
