Yes, Trutest has been developed specifically to this end. It is used normally to test against the maximum and minimum values printed on the base of the detector, or in the manufacturers’ data sheets. However, where manufacturers’ figures are unavailable, a site can still be tested, and individual detectors compared to the average values obtained for that site. 

Analogue addressable and intelligent sensors can only monitor the ‘clean air response’ or normal quiescent response of the internal sensor. This however does not test the actual alarm level, nor can it take into account variations in atmospheric conditions (dust, air movement, etc.). To determine the response of the sensors to smoke, they still need to be tested periodically with a controlled and measured source of test aerosol. By testing with Trutest can you be sure of the sensitivity to smoke and the
continuing accuracy of the sensor.

The total time required for a sensitivity test varies according to the type of test, the type of detector, and the sensitivity of the detector. Trutest works by gradually increasing the smoke density presented to the detector, therefore the more sensitive the detector, the quicker it will respond. Generally however, a test will take between three and five minutes, including the sensor initialization stage, and the final smoke clearing. In addition, the time taken to get to the next detector, and to position the Trutest unit should be added to give an overall idea of time.

Trutest is fully self-adjusting and re-calibrates itself at the start of a test. It therefore automatically takes account of any contamination within the system and adjusts to compensate for it. If this is a concern the user can perform his own tests with a detector of known quality at given intervals to prove this.

Trutest will no longer give results and the LCD will display a message to this effect (indicating a fault with the sensor). At this point the unit will need to be returned for service.

Extensive tests have been carried out to determine the effect of temperature on the performance of Trutest. As Trutest uses a liquefied gas aerosol canister, the critical operating temperatures are determined by the gas characteristics. The maximum operating temperature is limited to 95°F, as the maximum storage temperature for the aerosol canister is 120°F in line with international safety requirements.

The lower temperatures are, however, far more critical for the performance of the Trutest. If the aerosol canister temperature is too low, the internal pressure drops rapidly and produces too many large particles. This is normally seen when Trutest cannot reach the maximum obscuration level shown in the specifications, but shows a full-scale
reading at a lower level. The specified minimum operating temperature of 50°F, is very critical. At this temperature, the performance starts to rapidly drop off, and could affect the detector readings. Always check the room temperature as shown on the indicator strip on the side of the main unit, and ensure that the aerosol canister is at, or above, this temperature when testing. Note that the action of spraying the aerosol canister causes internal cooling. Therefore the more testing is performed, the lower the temperature drops in the main unit and aerosol canister.

TIP: Keep a spare Trutest aerosol canister in a warm (i.e. room temperature) place (e.g. in an office). When the temperature in the aerosol canister drops below 50°F (10ºC), exchange it with the warm canister. Also allow a slightly longer time than usual for recovery between tests. This will allow the main unit to recover to the ambient room temperature.

The particles of aerosol smoke used within Trutest, as with all smoke particles, are affected by very high levels of relative humidity. At high levels of humidity, where the air is saturated with water, the smoke or aerosol particles act as nuclei for small droplets of water to form. These are not seen as easily by the smoke detectors, and can give a false sensitivity reading. Additionally, as the release of the high-pressure contents from the aerosol canister has a cooling effect, the relative humidity level is reduced further, so that water particles start to form.

TIP: Relative humidity tends to be highest at sunset and sunrise in some climates (this causes dew). If the sensitivity readings for a number of detectors appear to be suspect in the early morning or late evening, it could be caused by high humidity. Try retesting these detectors in the middle of the day.

No. The tool is designed to use only the special Trutest aerosol canisters, and a different product would not work or give correct results. Other formulations could cause serious damage to both the detector under test and Trutest.

This depends on many factors; different types of test consume different amounts of power. In normal use the batteries last for 8-10 hours of continuous testing. If the tester is switched off whilst moving from detector to detector, this will give at least one full day of testing. The control unit display will prompt visibly and audibly if the batteries are low and it can be recharged overnight. In general, for each hour of charging, the unit will manage one hour of testing.

Only by hand. After a test has been completed the results are displayed on the LCD until the “Enter” key is pushed. They can be transferred manually to the results page that is found at the back of the manual. The last two results are stored in volatile memory and can be displayed by toggling the left arrow (“4”) key.

To a very limited degree. If the aerosol canister is tipped too much, it may not dispense the correct particle sizes. It may be better to exchange with detectors in more accessible positions. You should always ensure that the diaphragm seal properly seals the detector within the cup.

Yes, so long as a seal can be achieved with the diaphragm. Note that only the sensing chamber of the detector has to be sealed within the cup.