AUTOOL LM 120
Indicador de col·lector digital AUTOOL LM120+
Manual d'usuari
1. Producte acabatview
The AUTOOL LM120+ Digital Manifold Gauge is a professional instrument designed for comprehensive testing and maintenance of HVAC and refrigeration systems. It provides accurate digital readings for pressure, temperature, and vacuum, facilitating efficient diagnosis and servicing of air conditioners and refrigerators. This kit includes the main gauge unit, temperature probes, and connecting hoses, offering a complete solution for refrigerant management.

Figure 1: AUTOOL LM120+ Digital Manifold Gauge and included accessories.
2. Informació de seguretat
Please read and understand all safety warnings and instructions before operating the AUTOOL LM120+ Digital Manifold Gauge. Failure to follow these instructions may result in equipment damage, personal injury, or property damage.
- Always wear appropriate personal protective equipment (PPE), including safety glasses and gloves, when working with refrigerants.
- Ensure proper ventilation in the work area to prevent accumulation of refrigerant gases.
- No exposeu el dispositiu a temperatures extremes, llum solar directa ni humitat.
- Handle refrigerant hoses and connections with care to prevent leaks and refrigerant burns.
- No intenteu reparar ni modificar el dispositiu. Envieu totes les tasques de manteniment a personal qualificat.
- Verify that the selected refrigerant type on the gauge matches the refrigerant in the system being tested.
- Mantingueu el dispositiu fora de l'abast dels nens i de les persones no autoritzades.
3. Contingut del paquet
En obrir el paquet, comproveu que tots els elements que s'enumeren a continuació hi són presents i que es troben en bon estat:
- 1 x AUTOOL LM120+ Digital Manifold Gauge
- 2 x Temperature Clamp Sondes
- 3 x Refrigerant Hoses (Red, Blue, Yellow)
- 1 x Manual d'usuari (aquest document)
- 1 x Storage Case (if included with specific model variant)
4. Característiques del producte
The AUTOOL LM120+ offers a range of advanced features for precise HVAC system analysis:
- Evaporation Pressure & Temperature Test: Measures the maximum pressure when refrigerant changes from liquid to gas and the lowest temperature during this phase. This helps assess the efficiency of the cooling cycle.

Figure 2: Evaporation Pressure and Temperature Test display.
- Condensing Pressure & Temperature Test: Determines the minimum pressure when refrigerant changes from gas to liquid and the maximum temperature during this phase. Lower values indicate higher cooling cycle efficiency.

Figure 3: Condensing Pressure and Temperature Test display.
- High / Low Pressure Temperature Test: Measures the temperature of the refrigerant within the high-pressure and low-pressure pipelines of the air conditioning system.

Figure 4: High/Low Pressure Temperature Test display.
- Pressure Leakage Test: Calculates the pressure difference between an initial and a second test pressure to identify potential refrigerant leaks in the system.

Figure 5: Pressure Leakage Test display.
- Refrigerant Type Setting & Observation Window: Allows selection of the appropriate refrigerant type for accurate measurements and provides a viewable window to observe the refrigerant filling status.

Figure 6: Refrigerant Type Setting and Observation Window.
- Pantalla digital intel·ligent: Provides clear and intelligent digital display of test results for pressure and temperature, reducing diagnostic time.

Figure 7: Smart Digital Display.
5. Disseny i controls del dispositiu
Familiarize yourself with the components and controls of the LM120+ Digital Manifold Gauge:

Figure 8: LM120+ Digital Manifold Gauge Components.
| No. | Component | Descripció |
|---|---|---|
| 1 | Ganxo | For hanging the unit during operation. |
| 2 | Clamp-on Temperature Probe Socket | Connection point for temperature clamp sondes. |
| 3 | Pantalla LCD | Shows pressure, temperature, and other readings. |
| 4 | Botó de funció | Used to cycle through different functions. |
| 5 | Botó Run/Stop | Starts or stops measurement processes. |
| 6 | Botó zero | Resets pressure readings to zero. |
| 7 | R+/R- Refrigerant Type Selection Buttons | Used to select the type of refrigerant. |
| 8 | Botó d'atenuació | Ajusta la brillantor de la pantalla. |
| 9 | Botó Unitat | Changes measurement units (e.g., kPa, psi, bar). |
| 10 | Botó ° C / ° F | Alterna la visualització de la temperatura entre Celsius i Fahrenheit. |
| 11 | Botó d'engegada | Encén o apaga el dispositiu. |
| 12 | Refrigerant Observation Window | Allows visual inspection of refrigerant flow. |
| 13 | Vàlvula de baixa pressió | Controls flow to the low-pressure side. |
| 14 | Vàlvula d'alta pressió | Controls flow to the high-pressure side. |
| 15 | 1/4 inch Low Pressure Inlet | Connection port for low-pressure hose. |
| 16 | Vàlvula d'alleujament | Allibera l'excés de pressió. |
| 17 | 1/4 inch High Pressure Inlet | Connection port for high-pressure hose. |
| 18 | Refrigerant Inlet / Vacuum Pump Inlet | Central connection for refrigerant charging or vacuum pump. |
6. Configuració
- Instal·lació de la bateria: Open the battery compartment on the back of the unit and insert the required batteries (typically AA or AAA, refer to device markings if present). Ensure correct polarity.
- Encès: Premeu el botó Botó d'engegada (11) to turn on the device. The LCD display (3) should illuminate.
- Selecció d'unitats: Premeu el botó Botó Unitat (9) to cycle through available pressure units (e.g., kPa, psi, bar) and the Botó ° C / ° F (10) for temperature units. Select your preferred units.
- Calibratge zero: Before connecting to a system, ensure all valves (13, 14) are closed and the hoses are disconnected. Press the Botó zero (6) to calibrate the pressure sensors to zero. This ensures accurate readings.
- Connecteu les sondes de temperatura: Plug the temperature clamp probes into the Clamp-on Temperature Probe Sockets (2) on the top of the unit. Attach the clamps securely to the high and low-pressure lines of the HVAC system.

Figure 9: Connecting temperature probes and hoses.
- Connecteu les mànegues:
- Connect the blue hose to the Low Pressure Inlet (15) on the gauge and to the low-pressure service port of the HVAC system.
- Connect the red hose to the High Pressure Inlet (17) on the gauge and to the high-pressure service port of the HVAC system.
- Connect the yellow (or central) hose to the Refrigerant Inlet / Vacuum Pump Inlet (18) on the gauge. This hose will be used for vacuuming, charging, or connecting to a recovery unit.

Figura 10: Detallada view of hose connection points.
7. Instruccions de funcionament
This section outlines common operational procedures for the LM120+.
7.1. Selecting Refrigerant Type
- Amb el dispositiu encès, premeu el botó R+/R- Buttons (7) to scroll through the available refrigerant types (e.g., R134a, R22, R410a).
- Select the refrigerant type that matches the system you are working on. This is crucial for accurate pressure-temperature conversions.
7.2. Performing Pressure and Temperature Tests
- Ensure hoses and temperature probes are correctly connected to the system.
- Slowly open the high-pressure (red) and low-pressure (blue) valves on the manifold to allow refrigerant to flow into the gauge.
- The LCD display will show real-time pressure readings for both high and low sides, along with corresponding saturation temperatures based on the selected refrigerant.
- The temperature probes will display the actual line temperatures (T1 and T2).
- Compare the saturation temperatures with the actual line temperatures to determine superheat and subcooling, which are critical for system diagnosis.
7.3. Performing a Pressure Leakage Test
- Connect the gauge to the system and pressurize it to the desired test pressure (ensure system can handle the pressure).
- Tanqueu totes les vàlvules del col·lector.
- Premeu el botó Botó de funció (4) to navigate to the leakage test mode.
- Premeu el botó Botó Run/Stop (5) to start the leakage test timer. The gauge will record the initial pressure.
- Allow the test to run for a specified period (e.g., 15-30 minutes, or as per system manufacturer's recommendations).
- The display will show the elapsed time and the pressure difference. A significant drop in pressure indicates a leak.
- Premeu Botó Run/Stop (5) again to stop the test.
7.4. Refrigerant Charging/Evacuation
The LM120+ can be used in conjunction with a vacuum pump and refrigerant tank for system evacuation and charging. Always refer to the specific HVAC system's service manual for proper procedures and refrigerant amounts.
- Evacuació: Connect the yellow hose to a vacuum pump. Open the manifold valves and the vacuum pump valve to evacuate the system to the desired vacuum level. Monitor the vacuum reading on the gauge.
- Càrrega: After evacuation, close the manifold valves and disconnect the vacuum pump. Connect the yellow hose to a refrigerant tank. Purge the yellow hose of air. Slowly open the appropriate manifold valve (low side for vapor charge, high side for liquid charge with caution) to allow refrigerant into the system. Monitor pressure and temperature readings.
8. Manteniment
- Neteja: Wipe the device and hoses with a soft, damp drap. No utilitzeu productes de neteja abrasius ni dissolvents. Assegureu-vos que no entri humitat als components elèctrics.
- Emmagatzematge: Store the LM120+ in its original case or a protective container in a cool, dry place, away from direct sunlight and extreme temperatures.
- Substitució de la bateria: If the display becomes dim or the device does not power on, replace the batteries. Ensure the device is off before replacing batteries.
- Hose and Seal Inspection: Regularly inspect hoses for cracks, wear, or damage. Check O-rings and seals on connections for integrity to prevent leaks. Replace worn components as needed.
9. Solució De Problemes
| Problema | Causa possible | Solució |
|---|---|---|
| El dispositiu no s'encén. | Piles baixes o gastades; instal·lació incorrecta de la bateria. | Substituïu les piles per unes de noves, assegurant la polaritat correcta. |
| Lectures de pressió inexactes. | Gauge not zeroed; incorrect refrigerant selected; sensor malfunction; hose leaks. | Perform zero calibration; verify refrigerant type; check hose connections for leaks; contact support if issue persists. |
| Temperature readings are incorrect or absent. | Temperature probes not connected properly; damaged probes. | Ensure probes are fully inserted into sockets; check probe cables for damage; replace probes if faulty. |
| La pantalla està tènue o parpelleja. | Low batteries; display settings. | Replace batteries; use the Dimming Button (8) to adjust brightness. |
| Cannot select refrigerant type. | Buttons not responding; device malfunction. | Ensure buttons are pressed firmly; restart the device; contact support. |
10. Especificacions
| Paràmetre | Valor |
|---|---|
| Marca | AUTOOL |
| Número de model | LM 120 |
| Dimensions del producte (L x A x A) | Aprox. 210 mm x 120 mm x 65 mm (8.27 polzades x 4.72 polzades x 2.56 polzades) |
| Pes de l'article | 950 grams |
| Mida de la pantalla | 12 Inches (display area, not physical device size) |
| Compatibilitat amb refrigerants | Multiple common refrigerants (e.g., R134a, R22, R410a, etc.) |
| Unitats de pressió | kPa, psi, bar (selectable) |
| Unitats de temperatura | °C, °F (selectable) |
11. Garantia i Suport
For warranty information, technical support, or service inquiries regarding your AUTOOL LM120+ Digital Manifold Gauge, please contact AUTOOL customer service directly. Refer to the product packaging or the official AUTOOL weblloc web per obtenir les dades de contacte més actualitzades.
Please have your product model number (LM 120) and purchase information ready when contacting support.
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