Instruction Manual
InstruTech CVM-211 "
Stinger
" Convection Vacuum Gauge Module
InstruTech, Inc
page 5
Gases other than Nitrogen:
InstruTech gauges and modules are calibrated for N
2
. Do not attempt to use with other gases such as argon or
CO
2
unless accurate conversion data for N
2
to the other gas is properly used. Refer to Appendix B for a more
complete discussion of issues.
Do not use this device in an explosive atmosphere or in the presence of flammable gases or fumes.
Do not use this device to measure the pressure of explosive or combustible gases or mixtures. The sensor wire
in the gauge normally operates at 125
o
C, but under malfunction the wire temperature could exceed the ignition
temperature of combustible mixtures.
Installation
-
Mechanical
Mount the CVM as close as possible to the pressure
you want to measure. Long or restricted tubing will
create a pressure difference (error) between your
process and the gauge, and cause a delay in response
to pressure changes. Mounting the CVM too close to
a gas source will also cause errors in the readings.
Don't mount the CVM near a source of heating or
cooling, such as heaters or air conditioning vents.
Mount the CVM with its main (long) axis horizontal
(see diagram at right). Pressure reading errors will
occur above 1 Torr if the unit is not mounted
horizontally. (Below 1 Torr, mounting position has little
to no effect.)
Mount the CVM with port down, if possible, to help minimize the effect of any particles or condensation in the
gauge.
Don't mount the CVM where it will be subjected to excessive vibration, such as on mechanical pumps. Vibrations
may cause 'noisy' readings, and reading errors due to induced cooling of the sensor.
Fittings - follow the fitting manufacturer's recommendations and note the following:
- NPT fittings: Wrap the threaded portion of the tubing with Teflon
®
tape and hand tighten the gauge into the
gauge port. Do not use a wrench or other tool which may damage the gauge.
