Internal Gas Pressure Sensors - Teledyne T750 User Manual

I
NTERNAL
The T750 portable calibrator includes a single pressure regulator. Depending upon how
many and which options are installed, there are between two and four pressure sensors
installed as well.
In the basic unit a printed circuit, assembly located near the front of the calibrator near the
MFCs includes sensors that measure the pressure of the diluent gas and the source gas
currently selected to flow into the calibrator. The calibrator monitors these sensors.
Should the pressure of one of them fall below 15 PSIG or rise above 36 PSIG a
•
warning is issued.
In units with the O
rear of the calibrator just behind the generator assembly includes a sensor that measures
the gas pressure of the zero air flowing into the generator. A regulator is also located on
the gas input to the O
critical flow orifice to operate correctly.
Should the pressure of one of this sensor fall below 15 PSIG or rise above 25
•
PSIG a warning is issued.
In calibrators with O
measures the pressure of gas in the photometer's absorption tube. This data is used by the
CPU when calculating the O
083730750B DCN8606
G P S
AS RESSURE ENSORS
generator (option in the T750) installed, a second PCA located at the
3
generator that maintains the pressure differential needed for the
3
photometers installed, a second pressure located on the rear PCA
3
concentration inside the absorption tube.
3
159