Doc Ref: SL-068 v1.35 pg 14
Detector Zero Sequence
The module PCB has four inputs which can be enabled
and calibrated locally using the equipment set previously
described. When the module PCB is powered and as
described in the indications section, the LED’s will indicate
which options are enabled .
Option 1: Flammable Gas using Pellistor
Option 2: IR/PID/Toxic/Oxygen Detector
Option 3: Analogue 4-20mA Input 1
Option 4: Analogue 4-20mA Input 2
UP Button
DOWN Button
The zero sequence operates as follows:
1. Press the UP button until the LED’s go out, release the UP button.
2. Select the module address that requires zero by using the up/down buttons. With the correct
module input number displayed press and hold the UP button. Release when the LED’s go out.
3. Use the UP/DOWN buttons to select the left LED for zero mode (right LED is CAL mode) With
the left LED on, press and hold the UP button. Release when the LED’s go out.
4. With a zero gas flowing allow the detector to stabilise (usually 30-40 seconds). Note if a
display is fitted it will indicate the level at the same time.
5. With zero gas flowing and the reading stable press and hold the Up button to update the zero
point
6. Each LED will blink in series to indicate the update and the module will go back to normal
operation.
7. Press and hold the UP button to complete the sequence and return the module to normal
operation.
NOTE: There is no ABORT option so before selecting to zero ensure all necessary
equipment as previously indicated is available.
UP
UP
UP
DOWN
DOWN
DOWN
1 2 3 4 5
1 2 3 4 5
1 2 3 4 5
1 2 4 8 16
Module
Binary
Inputs
S YS T E M S TAT U S
S YS T E M S TAT U S
S YS T E M S TAT U S
S YS T E M S TAT U S
ch=pell
ch=1
mode
zero
Pre zero
0.6 lel
POST zero
0.0 lel
