MONIMET CH4-Monitor (Gasabsaugung)
Monimet 
CH4-Sensor/Transmitter Type GMm 01.13.xxx
CH4-Monitor Type GMm 01.13.xxx
I M1 Ex ia I Ma- Measuring range 0.0...100.0 vol % CH4
- Version for the gas suction treatment
- Thermal conductivity sensor with gas diffusion entry
- Pipe probe type RSM 01.xx with test gas connection (optional)
- Increased accuracy by compensation of prevailing humidity and temperature by microcontroller (patented)
- Integrated pressure compensation in the sensor chamber (optional)
- Illuminated four-digit display
- Output range of the output signal is variable
- Adjustments or status enquiries by means of a press button unit or a magnetic pointer. The housing need not be opened
- Code lock to prevent unauthorized manipulation (can be switched off)
- Fault self diagnosis with alpha numeric display
- Test of the output signal by simulated CH4 values
- Choice between normed analog or digital output signals (optional)
- Two built-in limit switches with optocouplers or relays in the monitor
- Special housing suited to the working conditions in mines and industry.
- Housing protection rating IP65, sensor protection rating IP 52
The permanently installed CH4-Sensor/transmitter and CH4-Monitor Type GMM 01.13.xxx are characterised by their stable measurements, simple and secure operation, robustness and compact construction. They are destined for the continuous monitoring of the methane concentration in gas suction pipes. The gas supply from the suction pipe is achieved by an pipe probe type RSM 01.xx. The pipe probe contains a dust filter and a connection for the test gases.
The measurement of the methane concentration in the sensor block is by means of an thermal conductivity sensor. The gas diffuses into the measuring chamber through a sinter metal disc. To increase the measurement accuracy a microcontroller continously compensates the prevailing temperature and humidity values. A built-in pressure sensor (optional) assures for a high measurement accuracy over a wide pressure range. A self monitoring microcontroller system not only processes the measurement values precisely, it also carries out the operator specific instructions such as the entry of the code, signal instructions and messages, analog and digital outputs and test functions etc. A four digit back lit graphic display shows the measured values in 12 mm high digits.
These devices conform to the explosion protection rating of intrinsic safety „i“, catagory I M1 Ex ia I Ma. This means that this device can be used in the zone M1 of underground mines, even when unpermitted high concentrations of the methane gas are prevailing.
This certification conforms to the ATEX directive 94/9/EG for devices and protective systems permitted for use in areas endangered by explosions.
The CH4-Monitor differs from the CH4-Sensor/transmitter because of an additional limit value unit which is equipped with optocouplers or relays.
The operation of the device is very simple: The operator places a small magnetic press button unit on the device. The housing need not be opened. As an alternative he can also use a magnetic pointer. A four digit code which can be entered initially, protects against unauthorized changing of the set values.
These devices are protected against shocks, dust and humidity by a cast metal housing (impact strength 20 Joule) and are to be connected by means of a plug-in connector. The sensor block with the CH4-sensor is attached on the lower side of the housing.
The adapter can be used for the mounting of the device. Alternatively a steel hanger or thread holes on its rear side can also be used for the mounting.
