User Manual PolyGard
®
2 Sensors 2023-11 Page 19 | 40
6.2.3 Calibration (Gain) with Surrogate Gas for Catalytic Sensor Element (Pellistor)
For certain gases it is possible to perform a cross calibration with methane (see Table 1).
The concentration of the calibration gas is calculated according to the following formula:
𝐶𝑎𝑙𝑖𝑏𝑟𝑎𝑡𝑖𝑜𝑛 𝑔𝑎𝑠 =
Gas concentration ∗ 100
Factor
6.2.4 Extended Calibration for Semiconductor Sensor Element
Caution:
Not applicable for Freon sensors with laser engraving 2000 ppm!
Applicable for semiconductor sensors for refrigerants with laser engraving 20–2000 ppm,
as well as ammonia, ethylene and Freon LFL sensors.
• Connect the multimeter (mV) to the test pin (marked in red Figure 3 and Figure 4) and GND
(pay attention to the connection diagram of the respective Board).
• Measure voltage against ground (GND).
• Caution: It is mandatory to use the GND of the Board to prevent a ground loop.
• Apply test gas to the Sensor (flow rate and application time according to Table 4 to Table 7,
and output pressure 1 bar ± 10 %).
• Set the voltage to 1650 mV ± 1 % using the potentiometer.
• After the gas application time has elapsed, remove the gas from the Sensor and wait (at least
6 hours) until the zero point has stabilised.
• Perform zero-point calibration (see chapter 6.2.1)
• Perform gain calibration (see chapter 6.2.2).
6.3 Calibration Analog Output
When recalibrating an MC2 Series Sensor, you have to recalibrate the analog output for the Sensor,
too. Otherwise, deviation between the digital display and the output current at the AO is to be ex-
pected.
Measure the analog output of the MC2 for correctness of the calibration value.
The permitted tolerance of the measured value is 2 %, measured via a 100 Ω/0.1 % precision resis-
tor.
If there is a higher deviation, calibrate the analog output according to the User Manual GA_STL06 or
GA_PCE06.
6.4 Test of MPS™ Sensors
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