Calibrating The Sensing Head Polytron Se Ex; Zero Adjustment; Sensitivity Adjustment - Dräger Polytron SE Ex PR NPT1 DD Instructions For Use Manual

Calibrating the Sensing Head
Polytron SE Ex
To achieve the state of thermal balance, the sensing
head needs to be in operation for at least 30 minutes
(warm-up time) before starting the calibration proce-
dure.

Zero Adjustment

Without calibration adapter:
Make sure that the sensing head is in clean air (free
of combustible gases and vapours),
or, with calibration adapter:
Apply zero gas (clean air or nitrogen) to the sensor
via calibration adapter, flow rate approx. 0.5 L/min.
Controller Unit Polytron with Channel Module
Polytron SE Ex:
1, 2 For channel mod-
ules without ana-
logue indicator or
with bar graph dis-
play connect volt-
meter
(R 1 MOhm) to
i
the sockets.
Sensing head Polytron SE Ex PR M1/2/3 DD, SE
Ex PR NPT1 DD and Polytron SE Ex HT M DD:
0 to 4.7 V correspond to a measuring range of
0 to 100 %LEL; so 1 %LEL = 47 mV.
Sensing head Polytron SE Ex LC M1/2/3 DD and
Polytron SE Ex LC NPT1 DD: 0 to 4.7 V corre-
spond to a measuring range of 0 to 10 %LEL; so
1 %LEL = 470 mV.
3 Use zero potentiometer to set indicator to 0 %LEL
(0 mV at voltmeter).
Controller Unit REGARD with Channel Module
REGARD Ex:
By means of menu »10-0 ZERO« set zero signal.
Please refer to the Instructions for Use REGARD Ex.
mV
=
1
2
3

Sensitivity Adjustment

When using commercial gases for calibration:
Depending on the sensing head used, apply span
gas with the recommended gas concentration (refer
to the table below) via calibration adapter to the sen-
sor, flow rate approx. 0.5 L/min.
Recommended span gas concentrations::
Sensing head
Polytron...
SE Ex PR M1/2/3 DD
SE Ex PR NPT1 DD
SE Ex HT M DD
SE Ex LC M1/2/3 DD
SE Ex LC NPT1 DD
The span gas should contain the target gas (gas to be
monitored) in a mixture with air..
Gases mixed with nitrogen are not suitable as span
gas!
When the reading has stabilized (after approx. 3 min-
utes):
Controller Unit Polytron with Channel Module Poly-
tron SE Ex:
4 Set the analogue
indicator with the
sensitivity potenti-
ometer to the val-
ue corresponding
to the span gas
concentration.
Sensing heads Polytron SE Ex PR M1/2/3 DD, SE Ex
NPT1 DD and Polytron SE Ex HT M DD: 0 to 4.7 V
correspond to a measuring range of 0 to 100 %LEL;
so 1 %LEL = 47 mV.
Sensing heads Polytron SE Ex LC M1/2/3 DD and
Polytron SE Ex LC NPT1 DD: 0 to 4.7 V correspond to
a measuring range of 0 to 10 %LEL; so
1 %LEL = 470 mV.
Examples:
Sensing head Polytron SE Ex PR M1/2/3 DD to be
calibrated with 45 %LEL:
Adjust to 45 47 mV = 2115 mV = 2.115 V.
Sensing head Polytron SE Ex LC M1/2/3 DD to be
calibrated with 5 %LEL:
Adjust to 5 470 mV = 2350 mV = 2.35 V.
span gas
full scale
concentra-
deflection
tion
100 %LEL 40...60 %LEL
100 %LEL 40...60 %LEL
100 %LEL 40...60 %LEL
10 %LEL 4...7 %LEL
10 %LEL 4...7 %LEL
CAUTION
mV
=
4
37