ZLLJYBLG GL77A Refrigerant Leak Detector — HVAC/Auto High-Sensitivity, LCD & Probe

The ZLLJYBLG GL77A is a handheld high-sensitivity refrigerant leak detector engineered to find halogen-based refrigerant leaks quickly and reliably.

If you service HVAC, refrigeration, or automotive A/C systems, locating small freon leaks fast saves time and prevents costly downtime. The GL77A combines a heat-dioxide semiconductor sensor, an adjustable probe, and both visual and audible alerts to help technicians and homeowners detect R134a, R1234yf, R410A, R22, R404A, R407C, R454B, R32 and other halogen refrigerants with industrial-grade sensitivity.

How precise is the GL77A at finding tiny leaks?

The detector reaches a maximum sensitivity equivalent to 0.49 oz/year (14 g/year), enabling it to identify very small refrigerant escapes. Its sensor and probe can detect leaks at close approach distances and low probe speeds for accurate pinpointing.

• Maximum sensitivity: 0.49 oz/year (14 g/year)
• Effective probe distance: ≤0.25 inches (0.63 cm)
• Recommended sweep speed: ≤3 inches/s (75 mm/s)
• Detects a wide range of halogen refrigerants including R134a and R410A

What alerts and readouts help me locate the leak quickly?

The GL77A provides both audible tones and on-screen visual feedback so you can confirm leaks in noisy or dim environments. A high-brightness LCD displays gas concentration, battery level, and alarm status while a UV light option helps visually trace dye or residue where applicable.

• Audible alarm for immediate feedback
• High-brightness LCD showing concentration and battery
• Visual UV light for leak visualization
• One-button ℃/℉ switch and intuitive control layout

How fast and easy is it to use during routine inspections?

The detector powers up quickly after a 30-second warm-up and is built with anti-interference circuitry to reduce false readings in complex environments. Ergonomic handheld form factor and simple controls (SEL, APO, ℃/℉, Power) make repeated inspections less tiring and straightforward for both pros and DIY users.

• 30-second automatic warm-up
• Anti-interference technology for stable readings
• Ergonomic grip and flexible probe for hard-to-reach areas
• Auto power-off and reset calibration for convenience

What power, portability, and accessories come with the detector?

The GL77A runs on two AAA batteries, which are included, keeping the tool lightweight and travel-ready for field service calls. A user manual is supplied so you can get started quickly, and the compact size fits easily into an HVAC toolkit or service bag.

• Powered by 2 x AAA batteries (included)
• Compact, handheld form factor for portability
• Includes user manual and flexible probe
• Auto power-off conserves battery during downtime

Who is this for? The ZLLJYBLG GL77A is designed for HVAC technicians, refrigeration service professionals, automotive A/C mechanics, and informed homeowners who need an accurate, portable tool for diagnosing halogen refrigerant leaks. It is ideal when you require sensitive detection, quick visual and audible confirmation, and a compact instrument that performs reliably in both workshop and field settings.