FOR ATMOSPHERIC CALIBRATION:
1. Turn the vacuum gauge on.
2. With the vacuum gauge at atmospheric pressure and constant temperature, press and hold
the ENTER button, then press the ALARM button. The display will read CAL – H.
3. Press ENTER to save the atmospheric calibration.
FOR DEEP VACUUM CALIBRATION:
NOTE: A reference vacuum gauge accurate at 1 to 100 microns is required for deep vacuum
calibration. For best results, calibrate around 50 microns. If your reference vacuum gauge does
not read in microns, the values will need to be converted to microns (mmHg or Torr x 10-3).
1. Turn the vacuum gauge on.
2. Press and hold the ENTER button, then press the
XX is the calibration pressure. Use the and arrows to adjust the calibration pressure to
match the reference vacuum gauge.
3. Press ENTER to save the deep vacuum calibration.
OPERATIONS
1. Press the
button to turn the unit on. The vacuum gauge's display will count down during
warm-up, then the pressure will be displayed. Above 20,000 microns, dashes will be
displayed.
2. Connect the vacuum gauge to the system and start the vacuum pump. Depending on the size
of the system it may take some time for the numeric vacuum reading to appear on the LCD.
The numbers descend from 20,000 Microns or corresponding units.
3. Press the
button to turn the unit off.
IMPORTANT NOTE REGARDING VACUUM LEAK TEST
When checking a system for leaks under high vacuum (less than 1000 microns), connect the
vacuum gauge directly to the system. If additional connections are required use copper tubing
(do not use rubber hoses) and high vacuum shut-off valves. Standard hoses and manifold gauge
set shut-off valves may have a small amount of leakage under high vacuum.
When initiating a high vacuum test, the vacuum gauge reading may "drift" higher until the
system has equalized. After this short stabilization period (5 minutes) the vacuum reading should
hold steady. An upward "drift" of the vacuum gauge reading may indicate a leaking system.
WARNING!! To prevent vacuum pump oil from getting in the vacuum gauge's senor, isolate
the vacuum gauge from the vacuum pump before turning the vacuum pump off. The vacuum in
the gauge can draw in vacuum pump oil if the vacuum pump is not running. If the AC system has
oil in it and is opened to atmosphere while the vacuum gauge is attached, this can cause oil to
get into the vacuum sensor as well.
MASTERCOOL CONNECT APP
1. Press the
key to power on the device
2. Download the Mastercool Connect app to a mobile device from the App Store or Google Play.
3. Launch the Mastercool Connect app on the mobile device.
4. Touch "SEARCH" on the Mastercool Connect app. From the list of available devices, pick the
digital vacuum gauge. The vacuum gauge should be listed as VGMastercool-xxx where xxx is
a unique number for the vacuum gauge.
5. Once the connection is made the Bluetooth ® wireless technology symbol will be displayed on
the left hand side of the digital vacuum gauge screen.
CLEANING THE SENSOR
Observe the gasket after each vacuum. If oil is present, it is possible that there is
a presence of oil in the sensor chamber. Follow these instructions:
1. Remove the gasket and depressor from the assembly.
2. Clean the gasket and depressor with acetone.
3. Using a syringe insert acetone into the fitting opening. Repeat until all of the oil is removed.
4. Use a gloved finger to cover the opening and shake the vacuum gauge. Allow to sit for a few
minutes.
5. Drain the solvent out into a suitable container for proper disposal.
6. Draw a vacuum on the sensor for 15 minutes to dry it out.
7. Repeat as necessary.
ERROR CODES
• E5 – Displayed momentarily if a deep vacuum calibration is attempted and the pressure in the
sensor is too high.
• For E1 to E4, Return to Mastercool for repair.
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button. CAL XX will be displayed where
3