STEL stands for Short Term Exposure Limit. This is the average amount of gas you can be exposed to in a 15 minute period with no long term health effects. This may occur 4 times a day. Industrial Scientific has different fixed-point monitoring systems for many gases and many applications. Please visit our fixed systems product section of the website Fixed Monitoring Systems .
Typical life is much greater than that.
A combustible sensor usually lasts in excess of 5 years. Typical life of CO and H2S sensors are 2-3 years. The MDU420 patented infrared sensor is warranted for a period of 5 years. We have a distribution network throughout the world. Our representatives are factory trained in the operation and maintenance of our products and handle a complimentary line of safety products.