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.