GAS70L Mercaptans Gastec Detector Tubes 0.1 – 8ppm

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GAS70L Mercaptans Standard Gastec Detector Tubes

Gas detector tubes are glass tubes that are filled with a chemical reagent that absorbs and reacts with the target gas or vapour being measured. Gastec tubes do not contain hazardous substances

A colorimetric stain (a colour change) is created. For most tubes, the concentration is read directly from the pinpoint accurate measurement scale on each tube.

The Gastec detector tube system is comprised of a handheld Gastec air sampling pump and Gastec detector tubes

Shelf Life – a1-cbiss will never dispatch detector tubes with less than 3 months remaining before expiry. a1-cbiss employ a stock rotation policy of first in, first out. Specific shelf life requirements must be identified at the point of order placement (use the comment box in the checkout process). The expiry date is printed clearly on the front of the detector tube packet.

To view the product specification, download product datasheet from the Product Downloads section


Q. When a Gastec tube user measured cattle dung with GAS70L Mercaptan tube, the tip of this tube turned black. What is this for?

A. Hydrogen Sulphide causes black colouring on the tip of GAS70L. The scrubber of Hydrogen Sulphide inside GAS70L reacted with Hydrogen Sulphide causing the tube to turn black. You can use the detector tube until the white layer completely changes to black.

Q. On several occasions a mercaptans tube GAS70L has shown a reading but quickly turned back to yellow. In both cases, we had ammonia near 30ppm and H2S below 5ppm. What would this be due to?

A. Actually, 5 ppm of H2S does not interfere, but around 30 ppm of ammonia interferes with the reading of GAS70L because the tube would bleach from the entrance.

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