Crowcon Detection Instruments

The Detective
The Detective is a free-standing, transportable gas detector and alarm unit that provides protection wherever there are shortterm hazards, such as during annual maintenance turnarounds. The unit can be used individually or in groups to monitor up to four gases at once. If a dangerous gas level is detected, the unit warns with a wailing 101-dB siren and flashing, high-intensity LED beacons visible from any direction. The Detective’s distinctive design incorporates a sturdy tripod that keeps the gas sensors raised above obstructions and away from surface water. An integral safety cage gives extra protection in the event of the unit being overturned. Sensors are available for oxygen, flammable gas and all toxic gases commonly encountered in industry. The Detective is intrinsically safe and protected against water and dust ingress. Power is provided by a sealed 6-V rechargeable battery giving up to 24 hours of continuous monitoring in quiescent mode.

Triple Plus+ IR monitors
Specially designed for the dangerous and potentially explosive task of emptying hydrocarbon storage tanks, reactors, pipelines or other vessels, the Triple Plus+ IR monitors the purge vent gas to determine when there is less than 100% LEL equivalent flammable gas concentration present. The infrared detector in the unit is a unique dual-range infrared sensor for flammable hydrocarbons scaled with both 0–100% volume and 0–100% LEL ranges, with an automatic range switch between these. This allows the earliest possible termination of nitrogen flow and a switch to air. Purge monitoring is also necessary in the reverse mode. Before hydrocarbon can be re-introduced, a low oxygen level is essential (usually <2% by volume). Nitrogen is therefore once again used to flush out the air, and the oxygen sensor fitted to the Triple Plus+ IR is used to monitor the falling oxygen content of the exhaust line. Once the oxygen content is low enough, the nitrogen flow can be stopped and the hydrocarbon re-introduced. The monitor is then used to follow the refill process to determine when full 100% hydrocarbon concentration is reached, allowing venting to stop.