I
nlet Connection 1 /8" NPT
OWNERS MANUAL
VG-1 · Digital Micn Gauge
Robinair
655 Eisenhower Drive.
Owatonna. MN 55060 USA
Customer Service: 1-800-533-6127
Technical Service: 1-800-822-5561
w.robinair.com
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Using the Magnetic Hook Assembly
The RA VG-1 comes with a unique Magnetic Hook Assembly which
allows you to 'hang' the gauge during operation or storage. It is
possible to use either the magnet alone or in combination with the
hook.
1. To attach the gauge with the magnet only, simply place the
back of the unit against any ferrous surface. The powerful
magnet will attach and hold the gauge.
2. To use the hook assembly, align the peg on the round disk
attached to the hook with the keyhole in the back of the gauge.
Insert the disk into the keyhole and now the traditional hook is
attached, and the gauge can be hung from a secure location.
OPERATING INSTRUCTIONS:
To Turn the Gauge On:
1. Press "ON/OFF� button on the lower right of the gauge front
once.
The gauge will begin a start up sequence: first displaying all
characters of the LCD and then a 10 second countdown.
NOTE: The backtight always remains off during this process.
After the countdown, the backlight will switch on. If you wish to
turn it off, simply press the yellow button above the display.
2. Once the gauge is ready to use it will display a nominal
indication of atmospheric pressure; as well as the enunciator
'ATM'. Depending on the units of measure selected the display
will show the theoretical value of 1 Atmosphere:
Microns: 76 000 (x10); inHg: 30.00; mBar: 1013; mmHg:
760.0; Pa: 10130; Torr: 760.0
NOTE: These values are simply indications of atmospheric
pressure (0 gauge pressure) to show that the gauge is not
detecting a vacuum. The RA VG-1 cannot be used as a
measure of true atmospheric pressure.
2. Start the vacuum pump, open service manifold valves and
system valves, if applicable.
3. The RA VG-1 may be switched on at anytime before or after
evacuation has begun. As the gauge measures true pressure,
it does not need to be switched on at atmospheric pressure.
a. The gauge will display the system pressure according to
the following table:
'
-
4. In most cases, it is only necessary to switch on the gauge at
the beginning of the evacuation process to verify that pressure
is decreasing. Unless it is a very small system being
evacuated, it is better to switch off the gauge to conserve the
battery until your analog gauges indicate that a deep vacuum
has been reached.
5. Once the system has reached a deep vacuum, switch on the
RA VG-1 to read the precise vacuum level in high resolution.
2. Start the vacuum pump, open service manifold valves and
system valves, if applicable.
3. The RA VG-1 may be switched on at anytime before or after
evacuation has begun. As the gauge measures true pressure,
it does not need to be switched on at atmospheric pressure.
a. The gauge will display the system pressure according to
the following table:
'
-
4. In most cases, it is only necessary to switch on the gauge at
the beginning of the evacuation process to verify that pressure
is decreasing. Unless it is a very small system being
evacuated, it is better to switch off the gauge to conserve the
battery until your analog gauges indicate that a deep vacuum
has been reached.
5. Once the system has reached a deep vacuum, switch on the
RA VG-1 to read the precise vacuum level in high resolution.
FIG. 3 Indicator of Vacuum below
atmosphere, but above 15 Torr
5
The battery should be replaced when no segments are visible inside
the indicator.
Auto Shut-O Feature
Your RA VG-1 is equipped with an Auto Shut-off feature which will
switch the gauge OFF in the event no changes in pressure are
sensed within a consecutive 15 minute period.
This feature will prevent unnecessary drain on the batteries.
It is not possible to disable this feature.
Pressure Overload
The RA VG-1 is designed measure ONLY negative pressure (from
atmospheric to zero absolute). It should NOT be exposed to positive
pressure. Applying pressure above atmospheric to the gauge may
cause failure and void your warranty.
Nevertheless, the gauge has been designed to withstand gradual
and temporary application of up to 27 ,5 Bar Gauge pressure without
sustaining any functional damage.
In the event positive pressure is applied to the gauge, no change in
display will be noted.
SPECIFICATIONS
Measurement Units
Microns (of Mercury), Inches of Mercury (inHg), MilliBars (mbar),
Millimeters of Mercury (mmHg), Pascals (Pa), Torr
Measuring Range:
From 15 Torr to Zero Absolute Pressure
Accuracy:
Above 5 Torr - ±10% of reading, below 5 Torr - ±5% of reading
Resolution:
From 15-5 Torr= 150 Microns/0.01inHg/0.333mbar/0.25mmHg/
33.33Pa/0.25Torr
From 5-2Torr = 50 Microns/0.002inHg/0.07mbar/0.05mmHg/
6.66Pa/0.05Torr
Below 2 Torr
=
5 Microns/0.002inHg/0.007mbar/0.005mmHg/
0.66Pa/0.005Torr
570819 REV C
