Ask us for the datasheet and a photo of the current revision.
GM700 Fixed Gas Detector
Fixed-point transmitter for continuous monitoring in classified areas, with relay and Modbus output for plant integration.
Overview
The GM700 is the fixed-point transmitter in the range: a detector that stays installed and reports continuously, instead of an instrument someone carries to a location.
Because it runs from a 24 V DC supply, it goes where a portable cannot: on a wall beside a pump seal, on a pipe stub in a gas yard, under a cover in a wet well. Relay outputs drive local alarm and ventilation directly, and the Modbus link carries the same value to the plant control system.
The series covers the standard industrial gas set across combustible, toxic and oxygen channels, including a laser version for methane over open paths.
Specifications
The parameter table for this model is being compiled. Ask us for the current datasheet and it will be sent by return.
Need the GM700 configured to your gas list?
Send the gases, the ranges and the host enclosure. We come back with a model recommendation, the datasheet and a price.
Technical background
The specification above only makes sense alongside the constraints behind it. These notes explain how the numbers on this page are usually set.
Why calibration needs a certified gas, not the air in the room
Zeroing in ambient air assumes the ambient air contains nothing. In a plant it usually does. Span needs a concentration that someone has measured and certified, or the instrument is being told a number that is not true.
Read the guide →Finding a duplicate Modbus address without pulling the loop apart
A duplicated address does not stop the bus. It produces one garbled reply and a working system, which is why it survives commissioning. The symptom is intermittent, so the diagnosis has to be systematic.
Read the guide →IP65 and IP66 differ by one digit and one washdown hose
The first digit is dust and both grades pass it. The second digit is water, and the gap between a 12.5 litre jet and a 100 litre jet is the gap between a hose and a pressure washer.
Read the guide →What a gas sensor costs over five years, not at the PO
A cell that costs half as much and lasts a third as long costs more. Five-year cost is dominated by replacement interval, calibration labour and the cost of the day it stops working.
Read the guide →Why 10% LEL and 25% LEL are both correct alarm setpoints
Two numbers appear on almost every combustible gas detector, and they are not competing recommendations. They do different jobs, and conflating them is how alarms end up bypassed.
Read the guide →