CMTOOL Digital Vacuum Gauge
About this document
- This document is an integral part of the instrument.
- Please ensure proper storage of this manual throughout the entire lifespan of the instrument.
- It is essential to utilize the complete original manufacturer's instruction manual.
- Prior to putting the product into operation, carefully read and familiarize yourself with this user manual.
- Pay particular attention to safety instructions and warning notices to prevent personal injury and damage to the instrument.
Safety
General safety instructions
- Operate the instrument in accordance with its intended use and within the specified parameter range as outlined in the technical datasheet.
- Avoid exerting excessive force when attempting to open the instrument.
- Refrain from operating the instrument if there are any visible signs of damage to the casing, main power source, or connecting cables.
- Adhere to locally recognized safety regulations when conducting measurements, as the test object or measurement environment may present potential risks.
- Avoid storing the product alongside solvents.
- Refrain from using any drying agents.
- Perform instrument maintenance and repair tasks strictly as described in this manual, following the prescribed procedures meticulously.
Waste disposal
- Dispose of faulty rechargeable batteries/waste batteries in accordance with applicable legal regulations.
- At the end of the instrument's lifespan, appropriately hand over the electronic components of the product to relevant entities for disposal. Please comply with local waste disposal regulations.
Technical Specifications
| Unit | 100Kpa/conversion | Resolution | Sensor error |
|---|---|---|---|
| mmHg | 750.061 | 0.001 | ± 0.1 % FS |
| InHg | 29.5299 | 0.0001 | |
| umHg | 750061 | 1 | |
| ftH2O | 33.4552 | 0.0001 | |
| cmH2O | 1019.72 | 0.01 | |
| InH2O | 401.463 | 0.001 | |
| Pa | 100000 | 1 | |
| Kpa | 100 | 0.001 | |
| mbar | 1000 | 0.01 | |
| bar | 1 | 0.00001 | |
| Kg/cm² | 1.01971 | 0.00001 | |
| psi | 14.5037 | 0.0001 | |
| Oz/in² | 232.060 | 0.001 |
SET VALUES FOR ALARM THRESHOLDS
| Unit | Setting range | Resolution |
|---|---|---|
| Kpa / psi | 0 ~ 100 / (0 ~ 14.000) | 0.1 / 0.001 |
| microns | 0 ~ 750000 | 0.01 |
Instrument Description
Purpose
- The purpose of this instrument is to accurately measure small pressure variations within a vacuum. It is a digital vacuum gauge that allows you to monitor the vacuum evacuation process in precision cooling systems and heat pumps, particularly during the debugging phase.
- By utilizing this instrument, you can obtain real-time pressure readings during the evacuation of the refrigeration system, thereby gathering valuable information about the degree of moisture removal and elimination of contaminants such as oil and external gases.
- The digital vacuum gauge is intended to be used in conjunction with a vacuum pump to create the vacuum environment. It is often paired with refrigerant gauges (analog or digital) to provide comprehensive monitoring of the cooling system.
Overview
| Component | Function |
|---|---|
| 1. Screen displays | Status icons, measurement units, and values. |
| 2. Control buttons | Used for operating the instrument. |
| 3. Brass tee and straight connector | Used for connecting refrigeration hoses, vacuum pumps, refrigerant gauges, etc. |
| 4. Battery compartment | Includes a 9V battery. |
Overview of the screen display
| Component | Function |
|---|---|
| 1. Temperature and calibration mode | Toggles between displaying the measured temperature and the calibration mode. |
| 2. Pressure value display | Displays the current measured pressure value. |
| 3. Pressure unit display | Toggles the display to show the currently selected pressure unit. |
Overview of the control buttons
| Component | Function |
|---|---|
| 1. UNITS button | Short press: Switch pressure units. Long press: Switch temperature units. |
| 2. Gear button | Long press to enter pressure alarm value settings. |
| 3. CAL button | Long press to enter calibration settings, automatically exits upon completion. |
| 4. MAX/MIN button | Short press: Toggle between MAX value and MIN value. |
| 5. Power button | Long press: Power on/off. Short press: Toggle backlight. |
| 6. Arrow buttons | Used for setting alarm pressure and adjusting other values. |
Standard Mode and Monitoring Mode
- By default, the device starts in normal mode. To enter the monitoring mode, short press the power button (with a power symbol ⏻), and press it again to exit the monitoring mode.
- In the monitoring mode, the screen displays a flashing SET indicator, and the buzzer emits a single beep every three seconds, with a frequency cycle of 1 Hz.
How to set pressure alarm value?
- Regardless of the mode (monitoring or standard), press and hold the gear button (⚙️) to access the pressure value setting interface. In this interface, the SET indicator remains on, and the screen shows six zeros "000000", with the decimal point positioned based on the selected unit. The rightmost zero starts flashing.
- To navigate through the numbers, press the arrow up/down buttons (⬆️/⬇️). Adjust the numbers from 0 to 9 using the arrow buttons. The valid range for settings is 0 ~ 99 kPa.
- Long press the gear button (⚙️) again to save the settings and exit.
Attention:
- Ensure that the set range does not exceed the maximum measurement range. For instance, if you choose kPa as the unit, the highest permissible setting is 99 kPa.
- If you input a pressure value beyond the established range, an error message "Error" will be displayed on the screen after saving the setting by long-pressing the gear button (⚙️). In such cases, the set pressure value becomes invalid and requires reconfiguration.
Precautions:
- After exiting, the device remains in Standard mode. Please remember to press the power button (⏻) again to re-enter the monitoring mode. If the current pressure falls below the set value, an alarm will be triggered.
- During an alarm, the backlight flashes, and the buzzer emits continuous beeps at a frequency of 1 Hz. The alarm will automatically cancel if the pressure exceeds the set value, or you can press any key to cancel it. Alternatively, the alarm will cancel automatically after 30 seconds, and the device will remain in monitoring mode.
Maintenance
Battery replacement
- Power off the device.
- Open the battery compartment.
- Remove the existing battery.
- Insert a new battery according to the markings inside the battery compartment.
- Close the battery compartment.
Instrument cleaning
Contaminants such as oil can affect the accuracy of the vacuum sensor. Follow these steps to clean the sensor:
- Prior to cleaning, ensure the device is powered off.
- Apply medical-grade alcohol to both interfaces.
- Gently shake the instrument for a brief period.
- Remove any residual alcohol from the instrument.
- Repeat this process at least twice.
- Allow the instrument to air dry for a minimum of 1 hour before the next use.
Warranty
Thank you for choosing CMTOOL products. CMTOOL provides the following services and promises:
- The warranty period of this product is 1 year.
- After the warranty period expires, repairs will be charged for replacement parts.
- After a failure, please contact CMTOOL customer service for the most complete service in the shortest time.
The following items are not covered by the warranty:
- Man-made faults are not covered by the warranty.
