AUTOOL LM110 Digital Manifold Gauge User Manual

Overview

This is an auxiliary instrument for installations, testing, and maintenance of refrigeration equipment such as air conditioners and cold storage. It features three main functions with digital readings and multi-unit switching. A built-in 89-refrigerant database provides more accurate readings.

The instrument is constructed with high-strength engineering plastic and flexible non-slip silicone for a solid and comfortable grip. It incorporates a 32-bit digital processing unit and a high-precision data acquisition unit for efficient and stable performance.

A large LCD display with backlight ensures clear readings and operation in dark conditions. A heavy-duty valve switch and 1/4-inch inlets make the instrument durable and versatile.

The built-in 89 types of refrigeration database allows users to intelligently check condensation and evaporation temperatures. The Vacuum Test and Pressure Leak Test functions, with leak time recording, meet users' needs for pressure testing and measurement during refrigerant filling.

Safety Rules and Precautions

This manual includes instructions and precautions for operation and maintenance. Failure to use the instrument in accordance with this manual could cause damage to the instrument. Design and production strictly follow IEC/EN61010-1 safety standard.

1. The pressure measured by the instrument is gauge pressure.
2. Pressure testing ranges from -101 Kpa to 6 Mpa (-0.1 bar to 60 bar).
3. Limit pressure is 10 Mpa (100 bar).
4. Maximum operation pressure of standard hose is 600 PSI (approximate 4.13 Mpa, 41.3 bar). The limit pressure for the hose is 3000 PSI (approximate 20.68 Mpa, 206.8 bar).
5. Please confirm the rated pressure value of the tested equipment before testing. Do not use it if it exceeds the range of the instrument. If the packed hose does not match the pressure requirement, other suitable replacements are available.
6. Do not use or store the instrument in environments with high temperature, high humidity, flammable, explosive, or strong electromagnetic fields.
7. Do not revise the internal circuit of the instrument to avoid any damage or danger.
8. Please wear qualified protective equipment during testing.
9. Please use the instrument in a well-ventilated environment to prevent inhaling toxic gases.

International Electrical Symbols

Specifications

Pressure Test: Gauge Pressure

Pressure Test Unit: Kpa; Mpa; bar; inHg; PSI

Pressure Test Range: 0 Kpa – 6000 Kpa

Pressure Test Resolution: 1 Kpa

Test Accuracy: +/- 0.5 %(FS) + 5dgt

Pressure Overload Limit: 10000 Kpa (10 Mpa; 100 bar)

Vacuum Test: Relative Vacuum

Vacuum Test Unit: Kpa; Mpa; bar; inHg; PSI

Vacuum Test Range: -101 Kpa – 0 Kpa

Vacuum Test Resolution: 1 Kpa

Built-in 89 kinds of Refrigerant NIST: (According to American NIST Standard)

Descriptions

Power Supply: 3 X 1.5V (SIZE.AA / LR6)

Dimension: 184 X 107 X 45.5mm / 7.3 X 4.3 X 1.8 inch

Weight (excludes battery): 0.446kg / 1 lb.

Instrument Diagram:

• 1- LCD Display: Shows readings and status.
• 2- POWER/BACKLIGHT Button: Short press to turn on/off backlight. Long press to power on/off the instrument.
• 3- FUNCTION/ ZERO Button: Short press to switch test functions (e.g., Pressure Test, Vacuum Test, Leak Test). Long press to zero the pressure reading.
• 4- SETTING Button: Short press to switch parameter selection within a function. Long press to enter setting mode (e.g., for parameter setting, leak test mode).
• 5- ARROW Button: Short press to increment a parameter value. Long press to change the direction of refrigerant selection.
• 6- Refrigerant Observation Window: Allows visual inspection of refrigerant flow.
• 7- Valve: Controls the flow of refrigerant.
• 8- 1/4inch Pressure Inlet: Port for connecting pressure hoses.
• 9- Refrigerant Inlet /Vacuum Pump Inlet: Port for connecting refrigerant or vacuum pump.

Function Instructions

6.1 Refrigerant Filling and Pressure Inspection

This function is used for refrigeration system repair, maintenance, refrigerant filling, and operation inspection. The built-in 89 kinds of refrigerant (NIST) provide pressure, condensation, and evaporation temperature data. Please read these two types of temperature when a pressure reading is obtained.

Operation Instructions:

1. Turn off the valve.
2. Press the POWER button to start the instrument. Press the FUNCTION button to select the Pressure Test Interface with Evaporation Temperature or Condensation Temperature.
3. The display will show 10 digits after the instrument is turned on. Long press the ZERO button to zero the reading.
4. Long press the SETTING button to enter setting mode for adjusting the unit and type of refrigerant (see 6.4 SETTING).
5. Fill refrigerant according to the instructive operation of the refrigeration system.
6. Obtain test readings for pressure test, running test, evaporation temperature, and condensation temperature.
7. Turn off the valve after filling is completed. Rapidly remove the connection between the instrument and the refrigeration system and refrigerant source.
8. Turn off the instrument.

NOTE: Filling operation for different equipment or refrigerant may vary. Please carefully read the relevant specific operation requirements for filling operation to avoid damage to the user or equipment caused by improper operation.

6.2. Vacuum Operation

Vacuum operation tests the vacuum pressure value and calculates the vacuum degree.

Operation Instructions:

1. Turn off the valve.
2. Press the POWER button to start the instrument. Press the FUNCTION button to select the Vacuum Test Interface.
3. Long press the SETTING button to enter setting mode for adjusting the unit (see 6.4 SETTING).
4. The display will show 10 digits after the instrument is turned on. Long press the ZERO button to zero the reading.
5. Operate vacuum according to the instructive operation of the refrigeration system.
6. Obtain test readings of vacuum pressure and vacuum degree.
7. Turn off the valve and vacuum source.

6.3. Pressure Leak Test

Pressure Leak Test is used for inspecting how much pressure changes over time after a refrigeration system has been filled with refrigerant or vacuumed.

Operation Instructions:

1. The instrument should be turned on with the valve turned off.
2. Press the FUNCTION button to select the Pressure Leak Test mode.
3. The display can show:
   • "△P": The small number at the top right corner refers to the difference value of pressure.
   • "STRT": The small number at the top right corner refers to the original pressure.
   • "TIME": The small number at the top right corner refers to the test time duration with the format "Hour : Minute".
4. Connect the instrument to the refrigeration system. Then, operate vacuum or fill some refrigerant into the system. Shut the valve and start the test by pressing the SETTING button when the reading keeps stable. The display will show a flashing delta signal.
5. At this time, the instrument records the original pressure and test period. Press the ARROW button to switch the display to see the difference value of pressure, original pressure, and test time duration, respectively.
6. Press the SETTING button again to stop the leak test.

6.4. Setting Operation

Types of refrigerant, pressure unit, and temperature unit can be changed as per the following instructions.

1. The instrument must be in any test function state.
2. Long press the SETTING button to display the setting interface.
3. The flashing parameter in the LCD display can be changed by pressing the ARROW button. The type of refrigerant selection increments forward in a single way (e.g., R1 → R2 → R3). Long press the ARROW button to change the selection direction.
4. Short press the SETTING button to switch parameter selection.
5. When all parameters are set, long press the SETTING button to save the selected item.
6. If the FUNCTION button is pressed accidentally during the process of setting parameters, the instrument will opt out and cancel all previous set items.

Common Problems

• 7.1 Low Battery Power Supply: The instrument includes a low battery indication (a battery sign at the top left corner of the LCD display). When it displays, batteries should be replaced promptly to obtain accurate test readings.
• 7.2 Damaged Hose or Valve Stem: Please check pipe fittings and hoses before testing. If any damage is visible, replace them immediately to avoid accidents.
• 7.3 Failure of Refrigerant Filling: There is a valve core in the refrigerant inlet of the system. When connecting the instrument to the system, pay attention to the two terminals of the hose. Connect one terminal with a core to the refrigeration system, and the other terminal without a core to the instrument.
• 7.4 Potential Leak Points: Every hose terminal comes with a nylon pad that has a certain service life. Please replace it when it is overused or flawed. Check the refrigeration system's pipes and other connectors.

Glossary

Saturation:

The state of saturation is the coexistence of a refrigerant in a liquid and gas state.

Condensation Temperature:

In the condenser, the refrigerant is condensed by the high-temperature gaseous refrigerant to the temperature of the liquid refrigerant, that is, the saturation temperature under condensing pressure.

Evaporation Temperature:

In the evaporator, the refrigerant evaporates from the liquid refrigerant to the temperature of the gaseous refrigerant, that is, the saturation temperature under evaporation pressure.

Degree of Subcooling and Superheat:

Subcooling: condensing temperature - condensing outlet temperature.

Superheat: evaporation outlet temperature - evaporation temperature.

A lower subcooling can improve the refrigeration capacity of the system. Adding a subcooling loop and economizer in the refrigeration system increases subcooling for refrigerant enhancement.

The degree of expansion of the expansion valve (refrigerant charge) affects the degree of superheat. The greater the degree of superheat, the smaller the opening of the expansion valve can be determined (meaning less refrigerant charge is needed).

Sensible heat and latent heat:

The amount of heat required to raise the water temperature from 0 degrees to 100 degrees is sensible heat. When water is heated to 100 degrees and becomes water vapor, the temperature remains at 100 degrees. The heat required for this process is called latent heat.

Gauge pressure and absolute pressure:

Gauge pressure: Refers to the pipeline pressure, or the pressure measured by pressure gauges, vacuum gauges, U-shaped tubes, etc. It is also known as relative pressure. The "table pressure" starts with atmospheric pressure and is symbolized as Pg.

Absolute pressure: The pressure directly acting on the surface of a container or object is called "absolute pressure". The absolute pressure value uses absolute vacuum as a starting point, symbolized as PABS (ABS is a subscript). Absolute pressure is atmospheric pressure + gauge pressure.

At atmospheric pressure, the gauge pressure is 0 and the absolute pressure is 1.013 bar.

Dry Bulb Temperature, Wet Bulb Temperature, Black Ball Temperature:

Dry bulb temperature: The temperature measured by ordinary thermometers.

Wet bulb temperature: A wet cloth is wrapped around the thermometer, and the temperature indicates a drop due to the evaporation of water. The temperature at this time is called the wet-bulb temperature.

A device that has both a dry bulb thermometer and a wet bulb thermometer is called a dry humidimeter, which can be used to measure the relative humidity in the atmosphere.

Black ball temperature: Also called actual temperature, it indicates the actual sensory temperature expressed by temperature when a person or an object is combined with radiant heat and convective heat in a radiant heat environment. The black ball temperature measured is generally higher than the ambient temperature, which is the air temperature.

Relative Humidity and Absolute Humidity:

Absolute humidity: The mass of water vapor in a unit volume of air is called the "absolute humidity" of air. It represents the physical quantity of atmospheric dryness and humidity. It is usually expressed in grams of water vapor contained in 1 cubic meter of air.

Relative humidity: The actual water vapor density in air and the percentage of saturated water vapor density at the same temperature are called the "relative humidity" of air. The degree of dryness and humidity of the air is related to the degree of saturation of water vapor contained in the air, but it is not directly related to the absolute amount of water vapor contained in the air.

After-sale Service

Warranty

AUTOOL offers repair service or replacement according to the specific type of the fault. All parts, accessories, and devices for replacement are guaranteed to be brand new.

AUTOOL will bear the shipping cost and offer corresponding accessories for replacement without charge if the customer sends video and pictures of the product failure within 90 days after receipt. If the product has been received for more than 90 days, spare parts will be provided for replacement without charge, but the buyer is supposed to bear other relevant costs.

The warranty is void if the product is:

• Bought through a non-official channel.
• Damaged due to improper use or maintenance not following the user manual.

Declaration

Please note that AUTOOL reserves the right to change product designs and specifications without notice. Images or descriptions in this manual are for illustration purposes only. Actual products may vary in terms of appearance and color. While AUTOOL strives to offer an accurate user manual, there may be slight differences. The right of final interpretation of the products belongs to AUTOOL, and AUTOOL will not be liable for any loss or damage caused by misunderstanding.

Contact Information

Company: Shenzhen AUTOOL Technology Co., Ltd.

Address: Shenhua Innovation Park, Baoan, Shenzhen, China

Website: www.autooltech.com

Email: aftersale@autooltech.com

Phone: +86-400 032 0988 / +86-755-27807580