Stupidly I used the pump for my roto (pre sensor) for recovery. So 2 gallons of oil and a new aspirator later, I’m ready to fire up my SPD setup.
Just got a mks 901p sensor, got it all hooked up. Ran my pump, got to 80 microns right at the head. After doing a oil change in the pump I got it down to 60. It’s a used pump (agilent ms40+) but was tested at 26 microns. Because I pulled solvent I might have to do another gallon of oil through, if not a rebuild, but going to try to get it to at least 30 microns at the head.
Looking at atmosphere pressure, it’s reading at 767 right now. It should be 760, or very close to. I am at actual sea level. Out of the box it was 762. Solvent air never hit the sensor.
That is well within the expected error amount (significant figures and all). The gauge does have different levels of accuracy through the different ranges of pressure. The manual has some very nice graphs that can clue you in. Another thing to consider is that the gauges have a setting that stores the calibration. My gauge did not come with the default calibration and was also set to Nitrogen instead of Air.
After I changed the gas setting and calibrated it I think it was reading 762.
I just read the manual again. The scientific notation threw me off. The unit is calibrated at zero, not high (atm) pressure. This was confusing to me because I used to work and calibrate transducers, but that was analog low voltage in a different industry measuring high pressure.
Here’s what the sensor states
100 Torr to Atm.: ± 25% of reading
So at 760 (atm) it can read from 570 to 950
For conversation sake and other users experiencing this, the sensor is accurate ± 5% in the range of
1×10-3 (0.001) to 100 Torr
The sensor combined with the script commander is a dream. After I get everything buttoned up, I’ll post a nice write up to compliment the other thread for the average user to put together.