A Comparison of Rate Compensated Heat Detector Test Methods
Overview of Rate Compensated Fire Detectors
Thermal switch technology invented by Wilfred J. Turenne in the 1920’s
Have been mass produced as fire detectors since the 1950’s
Examples of rate compensated fire detectors are Fenwal DAF (Detect-A-Fire) and Thermotech 302 heat detector
Detector function testing and calibration
Common heat detector regulatory requirements:
NFPA - National Fire Protection Association
Heat test shall be performed annually with a heat source per the manufacturer’s recommendations for response within 1 minute. A test method shall be used that is recommended by the manufacturer or other method shall be used that will not damage the.................temperature element.
Code of Federal Regulations
All fire- (flame, heat, or smoke) detection systems shall be tested for operation and recalibrated every 3 months provided that testing can be performed in a non-destructive manner. Open flame or devices operating at temperatures which could ignite a methane-air mixture shall not be used.
Bureau of Ocean Energy Management, Regulation and Enforcement
(Formerly The Minerals Management Service MMS)
Potential Incident of Non-compliance - PINC P-177:
…….ARE OPEN FLAME OR DEVICES OPERATING AT TEMPERATURES WHICH COULD IGNITE A METHANE-AIR MIXTURE NOT USED FOR TESTING?
Authority: 804(a)(9) Enforcement Action: C
INSPECTION PROCEDURE:
1. Review with operator the method used to test each fire-detection system.
2. Inspect device used in test for presence of open flame or temperature that exceeds 1100 F.
IF NONCOMPLIANCE EXISTS:
Issue a component shut-in (C) INC for the activity protected by each fire-detection system when the testing device uses an open flame or exceeds 1100 F.
Heat Detector Testing
Manufacturer requirements & recommendations:
Test methods: Heat gun, hair dryer, or heat lamp
“DO NOT overshoot the set point of the unit by more than 100°F (55°C), this could result in a shift of the set point temperature.”
“DO NOT contact the sensing shell with heating device such as a soldering iron or blowtorch as this will damage the unit and cause a shift of the set point temperature.”
“………….units are hermetically sealed and factory set, employing standard aluminum test blocks at the temperatures listed in the datasheet. A test kit with an aluminum block is required as it simulates factory test equipment. Heat transfer mediums such as liquid and air, or test equipment such as air, liquid or sand baths are not recommended and should not be used for testing purposes.”
Replacement is recommended if the detector is subjected to intense heat as in a fire