Smoke Detector Sensitivity Test Equipment

• Why test detector function and sensitivity?
• Applies to both conventional and intelligent systems
• Genuine ‘one test’ measurement
• Really simple to use
• Technical specifications

Detector sensitivity can, and does, drift. Over-sensitivity leads to false alarms, under-sensitivity to late alarms - or no alarms. The need for functional testing through introducing a smoke type stimulus is well recognised:

“Since stimulus of the sensing element through introduction of the phenomena or surrogate phenomena which the detectors are designed to detect forms part of the test(s), use of a test button or a test magnet (for example) or compliance with 45(i) (confirmation of analogue values) does not satisfy the recommendations..”
BS 5839 1: 2002 45.3 (Note 4)

“The detectors shall be tested in place to ensure smoke entry into the sensing chamber and an alarm response. Testing with smoke or listed aerosol...shall be permitted as acceptable test methods...”
USA NFPA 72 2000 Table 10.4.2.2 13.g.1

“Each smoke detector shall be tested for operation by introducing smoke or simulated smoke into the detecting chamber...”
CAN/ULC - S-536-04, 5.7.4.1.2

But the requirement for sensitivity checks is also clear in national standards:

“....tests shall be performed to ensure that each smoke detector is within its listed and marked sensitivity range...”
USA NFPA 72 2000 Table 10.4.2.2 13.g.1

“....each detector shall be tested to confirm that it is within its rated operating range...”
CAN/ULC - S536-04, 5.7.4.1.3

With its measured introduction of listed smoke aerosol to the sensing chamber of the installed detector, Trutest enables the functional and sensitivity checks to be combined within a single, cost effective test.

CONVENTIONAL DETECTORS

These detectors have no means of measuring their own sensitivity. Their sensitivity drifts, and so it should be tracked over a period of time, using Trutest.

ANALOG/INTELLIGENT DETECTORS

Interrogating the fire system panel of an intelligent system enables, at best, a check of the value of ‘clean air’ response levels. It does not verify the condition of the vents or ability of the detector to receive smoke into its sensing chamber. Correlating an unmeasured smoke source (e.g. hand-held can of smoke) with a panel interrogation also does not produce a quantified test, as US NFPA 72 confirms:

“...The detector sensitivity shall not be measured using any device that administers an unmeasured concentration of smoke or other aerosol into the detector”.
NFPA 72 2007 (10.4.4.2.6)

Some standards permit sensitivity test frequencies to be extended after proven detector stability. This relies on tracking drift, which can be done only by measuring actual sensitivity readings. Trutest does not need two tests to check the upper and lower limits (which, in itself, does not establish actual sensitivity). Just one test provides an actual reading in % / ft which can be compared year on year to establish drift. Other features include:

• Auto self calibration before each test
• Telescopic adjustment to over 20ft / 6m
• Battery charge for a complete day’s testing
• All hardware supplied in kit price quoted

• Assemble with ease
• Offer up to detector
• Select detector type and profile
• Start test
• Smoke level automatically increases until detector goes into alarm
• Stop test and take reading

By introducing a measured and controlled smoke stimulus into the sensing chamber, Trutest enables cross-references to be made between the independent Trutest readings and the analog readings from the system panel. Only in this way can a true test of intelligent systems be achieved.