CMTOOL Digital Vacuum Gauge User Manual

1. Introduction

The CMTOOL Digital Vacuum Gauge is a professional, high-precision micron vacuum sensor designed to quickly and accurately measure small changes in pressure within a vacuum system. It is ideal for monitoring vacuum evacuation processes in precision cooling systems and heat pumps, and for assessing moisture removal and contaminant elimination in refrigeration systems.

Figure 1: CMTOOL Digital Vacuum Gauge with included accessories.

2. Package Contents

Please verify that all items are present in the package:

• Digital Vacuum Gauge (with built-in 9V battery)
• 1/4'' SAE Extension Straight Joint
• 1/4'' SAE Tee Joint
• English User Manual
• Portable Carrying Bag

Figure 2: All components included in the CMTOOL Digital Vacuum Gauge kit.

3. Product Features

• High Precision Sensor: Utilizes a professional micron-level sensor for accurate measurements.
• 13 Pressure Units: Supports mmHg, inHg, umHg, ftH2O, cmH2O, inH2O, Pa, Kpa, mbar, bar, Kg/cm², psi, oz/in².
• Monitoring Mode & Sound and Light Alarm: Alerts users when pressure falls below a set threshold.
• Calibration Function: Allows for easy calibration to ensure measurement accuracy.
• Large HD Display with Backlight: 4.2CM×4.8CM screen provides clear data visibility in various lighting conditions.
• Temperature Unit Switching: Easily switch between Celsius (℃) and Fahrenheit (℉).
• Battery Level Display: Real-time battery indicator on the screen.
• Non-Slip Design: Rubberized sides for comfortable and secure handling.
• IP54 Dustproof Level: Suitable for various field tests.

Figure 3: Overview of the digital vacuum gauge's main features.

Figure 4: Close-up of the HD screen, battery level display, and non-slip rubberized design.

4. Setup

1. Battery Installation: The gauge comes with a built-in 9V battery. Ensure it is properly seated. The battery level will be displayed on the screen.
2. Connect to System:
   • Attach the 1/4'' SAE Male Fitting of the gauge to your vacuum system or pump.
   • Use the provided 1/4'' SAE Extension Straight Joint or 1/4'' SAE Tee Joint as needed for your setup.
   • Ensure the sealing gasket included in the package is used to prevent gas leakage.
3. Power On: Press the Power button to turn on the device.
4. Initial Calibration: Before each measurement, it is crucial to calibrate the product. Long press the CAL button to enter calibration mode. The gauge will automatically exit calibration upon completion. Failure to calibrate will affect measurement results.

5. Operating Instructions

5.1 Basic Operation

• Power On/Off: Press the Power button () to turn the gauge on or off.
• Backlight Control: When the gauge is on, short press the Power button to toggle the LCD backlight on or off.
• Normal Mode: The gauge defaults to normal mode upon power-on, displaying current pressure and temperature.

5.2 Monitoring Mode and Alarm

• Enter Monitoring Mode: From normal mode, short press the SET button (gear icon) to enter monitoring mode.
• Setting Alarm Value: In monitoring mode, short press the SET button to enter the alarm value setting. Use the Up/Down arrows to adjust the value and the UNITS button to switch digital positions. Long press the SET button to confirm the value.
• Alarm Function: If the current pressure falls below the set alarm pressure, the backlight will flash, and the buzzer will sound continuously. The alarm will automatically disappear when the pressure exceeds the set value, or after 30 seconds, or by pressing any key.

Figure 5: The gauge in monitoring mode, indicating alarm functionality.

5.3 Unit Switching

• Pressure Units: Short press the UNITS button to cycle through the 13 available pressure units (mmHg, inHg, umHg, ftH2O, cmH2O, inH2O, Pa, Kpa, mbar, bar, Kg/cm², psi, oz/in²).
• Temperature Units: Long press the UNITS button to switch between Celsius (℃) and Fahrenheit (℉).

Figure 6: The 13 pressure units and their measurement ranges/resolutions.

5.4 Max/Min Value Display

• Short press the MAX/MIN button to switch between displaying the maximum and minimum recorded pressure values.

5.5 Calibration

• Long press the CAL button to enter calibration mode. The gauge will automatically complete the calibration process and exit.
• Important: Always calibrate the gauge before each measurement for optimal accuracy.

Figure 7: Visual guide for calibration, Max/Min value display, and temperature unit switching.

6. Maintenance

• Cleaning: Wipe the gauge with a soft, dry cloth. Do not use abrasive cleaners or solvents.
• Battery Replacement: When the battery indicator shows low power, replace the 9V battery. Ensure proper polarity.
• Storage: Store the gauge in its portable carrying bag in a cool, dry place when not in use.
• Gaskets: Periodically inspect the sealing gaskets for wear and tear. Replace if necessary to maintain proper sealing and prevent leaks.

7. Troubleshooting

8. Specifications

Figure 8: Comprehensive technical specifications of the gauge.

Figure 9: Physical dimensions of the digital vacuum gauge and its included joints.

9. Warranty and Support

CMTOOL offers a 36-month warranty on this digital micron vacuum gauge kit. For any questions or support regarding this product, please feel free to contact CMTOOL customer service. We are committed to providing a satisfactory solution as soon as possible.