The MRU PU420 Pneumatic Auto Calibration is used only in combination with RT or HT models. It uses a permanently attached calibration gas cylinder. The pneumatic device is placed near to the probe up to 10m away. Instrument air or calibration gas is guided to calibration inlet port of the probe. The test gas (zero or span) is guided after moistening in the water bubblier to the calibration inlet port of probe detector flange and purging the sensing cells of the transmitter without the requirement to dismount the probe from the stack.
