Dräger Polytron SE Ex PR M2 DD User Manual

37
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:
z Make sure that the sensing head is in clean air (free
of combustible gases and vapours),
or, with calibration adapter:
z 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
i
t 1 MOhm) to
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:
z By means of menu »10-0 ZERO« set zero signal.
Please refer to the Instructions for Use REGARD Ex.
Sensitivity Adjustment
When using commercial gases for calibration:
z 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::
The span gas should contain the target gas (gas to be
monitored) in a mixture with air..
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.
01033176.eps
mV
=
3
1
2
Sensing head
Polytron...
full scale
deflection
span gas
concentra-
tion
SE Ex PR M1/2/3 DD 100 %LEL 40...60 %LEL
SE Ex PR NPT1 DD 100 %LEL 40...60 %LEL
SE Ex HT M DD 100 %LEL 40...60 %LEL
SE Ex LC M1/2/3 DD 10 %LEL 4...7 %LEL
SE Ex LC NPT1 DD 10 %LEL 4...7 %LEL
CAUTION
Gases mixed with nitrogen are not suitable as span
gas!
01133176.eps
mV
=
4

Dräger Polytron SE Ex PR M2 DD Specifications

General

Brand	Dräger
Model	Polytron SE Ex PR M2 DD
Category	Accessories
Language	English