Imperial LD-920 Nitrogen/Hydrogen Tracer Gas Leak Detector
The Imperial LD-920 is a tracer gas leak detector designed to detect the hydrogen component of a 5% hydrogen / 95% nitrogen tracer gas mixture. With sensitivity below 5 ppm and a sensor life rated at over 10 years, the LD-920 is suited to HVAC/R technicians and refrigeration mechanics who use tracer gas for leak detection on new or decanted systems where refrigerant cannot be used.
Important: The LD-920 detects the hydrogen component of tracer gas only. It cannot be used with straight nitrogen. The tracer gas mixture must contain hydrogen for detection to work. Always follow the manufacturer's instructions and relevant safety guidelines when working with pressurised systems. Pressure testing and system commissioning may require a licensed trade professional — confirm requirements with the relevant authority in your state or territory.
Key Features
- Sensitivity <5 ppm to N2/H2 tracer gas
- Heated sensor technology — sensor life >10 years
- Digital display showing relative leak size (1–9 scale)
- Automatic calibration and ambient reset
- Visual LED alarm near the sensor tip
- 3 selectable sensitivity levels
- Audio mute mode
- Fast warm-up — under 20 seconds
- 8 hours continuous battery life (4 x AA alkaline)
- Probe length: 43.8 cm (17")
Specifications
- Sensitivity: <5 ppm (N2/H2)
- Sensor life: >10 years
- Response time: Instantaneous
- Power supply: 4 x AA alkaline batteries
- Battery life: 8 hours continuous
- Warm-up time: <20 seconds
- Probe length: 43.8 cm (17")
- Display: 7-segment digital (1–9 scale)
- Weight: 0.57 kg (1.25 lbs)
- Certifications: CE, EMC Directive 2014/30/EU
- Warranty: 2 years from date of purchase
How Tracer Gas Leak Detection Works
Tracer gas (5% H2 / 95% N2) is a non-toxic, non-flammable, environmentally friendly mixture used to pressurise systems for leak detection without introducing refrigerant. Charge the system to approximately 500 kPa (75 PSI) with tracer gas. Because hydrogen is lighter than air, sample above suspected leak areas — welds, fittings, and joints. Keep the probe tip within 9.5mm of the surface and move at no faster than 75mm per second. The LD-920 will not detect straight nitrogen — the hydrogen component is required for detection.
What's Included
- Imperial LD-920 Tracer Gas Leak Detector
- 5 x sensor filters (Part # S77695)
- Leak test vial (Part # S77705)
- H2/N2 sensor with wand sensor tip and filter (Part # S77704)
- Wand sensor tip with filter (Part # S77698)
- Blow-moulded hard case (Part # S77707)
- 4 x AA 1.5V alkaline batteries
Best For
- HVAC/R technicians and refrigeration mechanics using tracer gas for leak detection
- New system pressure testing where refrigerant cannot be used (confirm licensing requirements)
- Decanted system leak checks before recharging
- Applications where an environmentally friendly, ventable leak detection method is required
Check Before Ordering
- The LD-920 detects H2/N2 tracer gas only — it will not detect refrigerants or straight nitrogen
- Tracer gas must contain hydrogen for detection to work
- Pressure testing and system commissioning may require a licensed trade professional — confirm with the relevant authority
- Replacement sensor filters are consumables — stock spares (Part # S77695)
- Warranty: 2 years from date of purchase; consumables excluded
Frequently Asked Questions
Can the LD-920 detect refrigerants?
No. The LD-920 is designed to detect the hydrogen component of N2/H2 tracer gas only. For refrigerant leak detection, see our refrigerant leak detector range.
Can I use straight nitrogen with the LD-920?
No. The LD-920 detects hydrogen — the tracer gas mixture must contain hydrogen (5% H2 / 95% N2) for the detector to work.
How do I use tracer gas for leak detection?
Charge the system to approximately 500 kPa with tracer gas. Sample above suspected leak points — hydrogen rises, so check above welds, fittings, and joints. Keep the probe within 9.5mm of the surface at no more than 75mm/sec. Refer to the operator's manual for full instructions. Pressure testing may require a licensed trade professional — confirm requirements in your state or territory.
What is the warranty?
2 years from date of purchase. Consumables including filters, batteries, and sensors are excluded. Confirm current terms with HVAC Trade Supply at time of purchase.
Browse our full leak detector range or contact our team for advice on tracer gas detection.