5 How to Operate
5-5. Description of operation (detection mode)
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5-5-2. External output operation
4 – 20 mA transmission
(1) Signal transmission method
: Electric current transmission (non-isolated)
(2) Transmission path
: CVVS 2c 1.25 sq
(3) Transmission distance
: 500 m or less
(4) Connection load resistance
: 300
Ω
or less
(5) Status signal level
1. Detection mode
: 4.0 - 20.0 mA (depends on the gas concentration)
2. Initial clear
: 4.0 mA
3. Maintenance mode
: 4.0 mA or lower
4. External output test
: 4.0 - 20.0 mA (varies with the test value)
5. Fault state
: 3.5 mA
6. Power off
: 0.0 mA
The following figure shows the relation between "gas concentration" and "external output".
4 mA
20 mA
20.5 mA
Full scale
Gas concentration
External output
0
Zero suppression value
Detection mode
Maintenance mode
Maintenance mode
CAUTION
The 4 - 20 mA output is adjusted. If readjustment for 4 – 20 mA is needed after installation, it must be
done by a qualified service engineer.
