9. Sensor Zero is true when D1 flashes orange and potentiometer VR2 is adjusted to ensure Adj is
between 400 and 600. VR2 clockwise will increase Adj. (Note pressing (R) or J28 short will reset
sensor and give 1 min adj time)
10. Press F to adjust the 4mA output by measuring the mV across TP8 and TP9. Press H and L to set
and then press SPACE to exit.
11. Press T to adjust the 20mA output by measuring the mV across TP8 and TP9. Press H and L to
set and then press SPACE to exit.
12. Before using span gas, ensure that an Autozero is not about to take place, indicated by the fault
LED not flashing. The fault led on the PCB will flash during Power up but also when there is less
than 30 seconds to an autozero.
13. Apply a test gas to the sensor (mid-range 500ppm is preferred) for 2 minutes at a flow rate of
1 litre/min. Use the UP and DOWN buttons on the PCB to give correct 4-20mA level. (ie 12mA
for 500ppm). Remove gas and wait 5 minutes. If a maximum range gas is available, apply for
2 minutes and note the value of A. This can then be entered using Hyperterminal using the M
command giving better accuracy above the mid calibration gas level. Remove gas and wait 5
minutes.
14. Connect the sensor to a Combi alarm panel and ensure that it reports in correctly.
Note: Fit the end of line (EOL) link J1 if the sensor is to be installed at the end of the sensor
cable.
15. If front panel display board is fitted via connector J5 and U12 adjust VR1 for LCD contrast.
16. Remove J9 test link for normal operation.
17. Ensure J29 address link is removed (this is only used when changing address from a Panel)
Manual calibration (without PC or LCD)
Auto zero is operating
18. Zero - with no gas applied, auto zero is in operation and LED D should be flashing orange. Check the
voltage between Ag and S16 to be 450mv approx. With J9 test link inserted the 4-20mA output signal
measured at TP8 to TP9 should be 4mV.
19. Span - ensure that auto zero is not within 30 seconds indicated by the MPV LED short flash, then apply
test gas (typically 50%) for 2 minutes and use the UP and DOWN buttons to adjust the 4-20mA output
current to the correct value, eg 50% gas would give 12mv. Remove gas and ensure output current falls
to 4mA. Note this may take some time as the semiconductor returns to normal. Remove test link J9.
Using magnets (set up)
WIN versions of the sensor have an LCD display which shows the Gas and range together with the
sensor address and a display of the number of seconds until an autozero will occur.
Also incorporated are 3 reed switches which can be activated using external magnets through the
glass window of the flameproof XDIwin enclosure. These magnets do not act instantly and have
to be in close proximity to L, M and R on the front display for a few seconds to activate a software
setup function.
The right magnet allows the CAN address of the sensor to be changed. When the address menu is
displayed with a prompt to remove the magnet, and then the display shows the address and that
the right magnet will decreases it whilst the left magnet will increase it. This is then stored in internal
non-volatile memory and the display will automatically revert to normal operation.
The centre magnet is used to inhibit the sensor. As with the left and right magnet functions the
display requests that you remove the magnet and then the state of inhibit appears on the LCD.
The left magnet then puts the sensor into inhibit whilst the right magnet removes it. The amber
LED on the front panel under the LCD flashes when the sensor is inhibited. When all magnets are
