ANNOVEX NO2-Sensor
ANNOVEX NO2-Monitor with AVS 3
ANNOVEX 
NO2-Sensor/Transmitter Type GMA 14.05.xxx
NO2-Monitor Type GMA 14.05.xxx
I M1 Ex ia I Ma- Linearized measured value display from 0.0...20.0 ppm NO2
- Electrochemical measurement process with gas diffusion entry
- Increased accuracy by compensation of prevailing air-pressure and temperature by microcontroller
- Output range of the output signal is variable
- Illuminated four-digit display
- 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 NO2 values
- Choice between normed analog or digital output signals (optional)
- Two built-in limit switches with optocouplers or relays in the monitor
- Audio visual alarm optional (Monitor)
- The sensor can be replaced on site
- Housing protection rating IP65, sensor protection rating IP 52
The economical, permanently installed NO2-Sensor/transmitter and NO2-Monitor are characterised by their stable measurements, simple and secure operation, robustness, low weight and compact construction.
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 NO2-Monitor differs from the NO2-Sensor/transmitter because of an additional limit value unit which is equipped with optocouplers or relays.
The measurement of the nitrogen dioxide concentration in the sensor block is by means of an electrochemical 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 air-pressure values. A primary filter, which can be easily replaced, protects the sinter metal against dirt. The test gases can be fed into the measurement chamber by means of a plug-on adapter of the type PGA 3.
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. 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 are placed in a fibre reinforced resin housing (impact strength 7 Joule) and are to be connected by means of a plug-in connector. The sensor block with the NO2-sensors is located next to the connector and it can be replaced easily on the underground site.
For the suspension of the device a steel hanger is attached. Holes on the back of the device permit a rigid mounting. In addition the NO2-Monitor can be equipped with an audio visual alarm unit for giving alarms in the monitored area (see opposite illustration).
