f)Adjust outside pot to read 2.630mV ±5∝V on DVM.
g)
Courseadjustment
(Caution:Resistorconnectionsarenottoanypowerterminals.)
a)Withpoweroff,connectan86.6ohm1%1/8Wresistortotubeterminalswhite&green.
b)Connecta28ohm1%1/8Wresistortotubeterminalsredandblack.
c)ConnectaDVMtomeasuremVacrossthe28ohmresistorwith(+)leadtoredterminal.
d)Withpoweron,adjusttrimpotonrightsideofcan(Viewedfromfrontdisplay.)
to set 350mV ±0.5mV.
e)Setunitsdisplaytoread0.00byadjustingzeropotatrearofcan.
f)
g)Withpoweronadjustspanpotatrearofcantilldisplayreads15.00Torr.
Hastings)
Fine adjustment.
Due to bridge loading, you will need to readjust zero and span pots using a good or above calibrated DV- 273.
a)Connect and run unit for 30 minutes at hard vacuum (< 1mTorr) so system may out gas.
b)Readjust zero pot at rear of can if necessary, to set display to read 0.00 Torr.
c)Using a Primary standard, bring system up to 15.000 Torr ±1mTorr.
d)Readjust span pot at rear of can if necessary, to set display to read 15.00 Torr.
e)Fine Calibration is now complete.
5.3Check Against Primary Standard:
If additional calibrations of the vacuum gauge are desired, an accurate measuring device such as the McLeod Gauge, spinning rotor gauge, or capacitance manometer may be employed as a reference. Please refer to manufacture for the suitability requirements. Please read Sec. 6.
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