AUTOOL LM120 · Dual-Pressure Digital Manifold Gauge with Temperature Inputs
Control Both Sides and Calculate SH/SC
Measure high- and low-side pressure across 0–6 MPa, monitor relative vacuum and support refrigerant charging with this digital manifold gauge. Compatible clamp probes, included only in selected packages or purchased separately, provide -40°C to 150°C pipe-temperature readings and enable superheat/subcooling calculations with the correct refrigerant selected. Timed pressure retention, 1/4-inch interfaces, valves and a backlit display support daily service.
- 0–6 MPa Gauge Pressure
- -40°C to 150°C with Probes
- Superheat / Subcooling
- Timed Pressure Retention
- 1/4-Inch Connections
Key Features
Pressure and Two Temperature Inputs on One Display
Dual Pressure Measurement
Read high- and low-side gauge pressure together with dual temperature measurement during installation, testing, and service.
Dual Display Temperatures
Display two pipe temperatures when compatible clamp probes are connected and seated correctly.
Probe Temperature Range
Temperature measurement range: -40°C to 150°C with compatible clamp probes.
Superheat And Subcooling Support
With the correct refrigerant selected and compatible probes connected, calculate SH and SC from pressure and pipe-temperature data.
Vacuum Monitoring
Follow relative vacuum during an approved evacuation procedure before charging.
Timed Pressure-Retention Test
View initial pressure, current pressure, pressure difference and elapsed time to assess system tightness. Pressure inspection, refrigerant filling assistance and vacuum monitoring support the service sequence, with switchable pressure and °C/°F units.
Refrigerant Charging Assistance
The built-in 32-bit digital processing unit and refrigerant database support direct reading of operating data and calculation of superheat and subcooling when required accessories are connected. Use selected refrigerant data, readings, valves and properly rated hoses to support the equipment-specific charging procedure.
Backlit Multi-Unit Display
Read service data on the large backlit LCD and switch pressure or °C/°F units to match the procedure.
Durable Service Controls
High-strength engineering plastic, flexible non-slip silicone grip, long-life valve switches, and 1/4-inch standard interface improve durability and versatility.
3 Years Warranty Support
Main unit: 3-year warranty. Standard accessories: 1-year warranty. Warranty Policy.
Safety & Compatibility
Match Refrigerant, Hose, Port, and Pressure
Do Not Confuse Limits
The working measurement span, 10 MPa instrument limit, 600 PSI hose working rating and 3000 PSI hose limit are separate values.
Confirm Refrigerant Identity
Select the known refrigerant in LM120 before interpreting pressure and temperature data or charging.
Inspect Hoses And Fittings
Replace damaged hoses, seals or fittings and use a suitably rated hose if the supplied one does not meet the job.
Use PPE And Ventilation
Wear appropriate protection, ventilate the work area and keep the instrument away from heat, humidity, ignition hazards and strong electromagnetic fields.
Follow Equipment Procedures
Different systems and refrigerants require different connection and charging sequences; follow the current manual and equipment maker’s instructions.
Restricted Operating Environments
Do not use or store the instrument in high temperature, high humidity, flammable, explosive, or strong electromagnetic field environments.
No Circuit Modifications
Do not modify the internal circuit, because it may damage the instrument or create danger.
Inspect Leak-Test Connections
Check pipe fittings, hoses, and valve stems before leak testing. Replace damaged parts immediately.
Follow Refrigerant Procedures
During refrigerant filling, follow the specific operation requirements of the equipment and refrigerant to avoid damage to the user or equipment.
Release Pressure Before Disconnecting
Do not remove the high-pressure valve connection until the pressure drops to a safe point.
Test Results
Read Paired Pressure and Temperature Values
High/Low Pressure Pair
Interpret high- and low-side pressure with refrigerant, temperature and operating condition.
Superheat/
Only interpret SH/SC when the correct refrigerant is selected and probes have stable full pipe contact.
Pressure Difference Over Time
A changing retained pressure can indicate a setup or system-sealing issue; repeat the setup check and use a separate approved method to locate the cause.
Vacuum Trend
Compare the achieved/stable vacuum with the service specification rather than using a universal runtime rule.
Specifications
LM120 Specifications
| Selection Criteria | |
|---|---|
| Core workflow | Pressure, vacuum, retention and charging assistance |
| Temperature probes | Supported; inclusion varies |
Manual & Downloads
Use the Manual for Setup and Service
AUTOOL LM120 User Manual
Open the PDF manual for LM120 pressure and temperature measurement, superheat and subcooling calculations, vacuum checks, refrigerant charging, safety, and troubleshooting.
Package
What’s Included
- LM120 Main UnitDigital AC manifold gauge.
- Red, Blue And Yellow HosesColor-coded service hoses; confirm the pressure rating and selected configuration.
- Adapters/CouplersConnection accessories; exact pieces require confirmation for the selected kit.
- Storage CaseProtective case.
- Manual And Retail BoxDocumentation and retail packaging.
- Temperature Probes And BatteriesDo not assume inclusion; confirm the LM120 configuration. The instrument requires four AA batteries.
FAQs
A/C Manifold Gauge Connection and Reading Questions
Does LM120 identify refrigerant?
Select the known refrigerant before interpreting readings or charging.
What Is AUTOOL LM120 Used For?
AUTOOL LM120 is a digital manifold gauge used as an auxiliary instrument for installing, testing, and maintaining refrigeration equipment such as automotive A/C systems, air conditioners, and cold storage systems. It supports dual pressure testing, dual temperature testing, vacuum measurement, pressure leak testing, refrigerant filling assistance, and multi-unit conversion.
- It measures high/low gauge pressure, relative vacuum and compatible probe temperatures, and supports a timed pressure-retention test.
Can LM120 Calculate Superheat And Subcooling?
Yes. LM120 calculates superheat and subcooling when the correct refrigerant is selected and compatible temperature probes are connected and fully seated. Probe availability depends on the selected package or model version.
Can it locate a leak?
No. A pressure-retention change can flag a sealing concern, but a separate approved method is needed to locate the cause.
What Is The Standard Hose Pressure Rating?
The standard hose maximum operating pressure is 600 PSI, about 4.13MPa / 41.3bar. The hose limit pressure is 3000 PSI, about 20.68MPa / 206.8bar. If the packed hose does not match your pressure requirement, use a suitable replacement hose.
- Use the lowest applicable working rating among the system, gauge and hose; do not use instrument or hose limit figures as operating targets.
What batteries are needed?
Four 1.5 V AA/LR6 batteries; confirm whether they ship in your region.
How Many Refrigerants Does LM120 Support?
The LM120 manual lists a built-in database of 89 refrigerants based on American NIST standard data. Some comparison materials may show different refrigerant counts by version, so confirm the current model version if the exact database count is critical for your use.
- Both share the core manifold workflow. LM120+ is a separate configuration associated with the three-color hose set and two wired temperature-clamp support; verify each package before purchase.
Does LM120 Measure Gauge Pressure Or Absolute Pressure?
LM120 measures gauge pressure. Gauge pressure starts from atmospheric pressure, while absolute pressure starts from absolute vacuum. Confirm the tested system requirement before using the instrument.
What Is The LM120 Pressure Range And Limit?
The LM120 pressure measurement span is 0–6000 kPa, and its relative-vacuum span is -101–0 kPa. Overall coverage is -101 kPa to 6 MPa (approximately -1.01 bar to 60 bar), and the instrument limit pressure is 10 MPa (100 bar). Do not use the instrument if the tested equipment exceeds the instrument range.
What Batteries Does LM120 Use?
LM120 uses 4 × 1.5V AA / LR6 batteries. Replace the batteries when the low battery sign appears to avoid affecting normal use. Batteries may not be included, depending on shipping and package configuration.
What Should I Check Before Pressure Leak Testing?
Check pipe fittings, hoses, and valve stems before testing. If any damage is found, replace the part immediately to avoid improper use or accidents. During leak testing, LM120 records initial pressure, instantaneous pressure, pressure difference ΔP, and test duration.
What May Cause Refrigerant Filling Failure?
Refrigerant filling failure may be related to hose connection direction, system pipe or connector issues, or air remaining in the hose. The middle refrigerant inlet has a valve-core port used to vent air after connecting refrigerant to the instrument. Tighten the copper plug screw before or after each operation and check the refrigeration system pipes and connectors.
What Is The Difference Between LM120 And LM120+?
LM120 is the core digital manifold gauge model for vacuuming mode, refrigerant mode, and pressure leak testing. LM120+ keeps the main LM120 workflow and adds trichromatic tube and two wired temperature clamps according to the comparison chart. Choose based on whether you need the added accessory configuration.
How Should I Maintain And Store LM120?
Keep the instrument dry and avoid hot, humid, or non-ventilated storage. Check tightened and connected parts regularly, treat parts that contact chemical media with anti-corrosion care when needed, avoid corrosive liquids, and do not overload the instrument.
How Long Is The Warranty?
Main unit: 3-year warranty. Standard accessories: 1-year warranty. Warranty Policy.
