Testo 770-1 TRMS Clamp Meter
- Measure Smarter. Work Safer. Get Results Faster.
Take control of your electrical measurements with the testo 770-1 – the TRMS clamp meter built for accuracy in tight spaces.
👉 Request pricing or speak to an expert today and see how the testo 770-1 Clamp can simplify daily diagnostics while improving safety on site.
testo 770-1 – TRMS Clamp Meter for Professional Electrical Work
The testo 770-1 is a professional-grade TRMS clamp meter designed for electricians, maintenance engineers, and HVAC professionals who need reliable results in confined environments. Purpose-built for measurements in crowded switching cabinets, the testo 770-1 Clamp combines intelligent automatic measurement detection with a unique mechanical design that sets it apart from conventional clamp meters.
Its fully retractable pincer arm allows safe, non-contact current measurement on tightly packed conductors, while True RMS technology ensures dependable accuracy even with distorted signals. The testo 770-1 is the ideal choice for fast, confident electrical testing in real-world conditions.
Why Choose the testo 770-1 Clamp?
Built for Tight Switching Cabinets
The standout retractable pincer arm allows the testo 770-1 to grip individual conductors effortlessly, even where space is extremely limited. This improves safety, visibility, and efficiency during live measurements.
True RMS Accuracy for Modern Loads
With TRMS measurement, the testo 770-1 Clamp delivers precise readings on non-linear loads, making it suitable for modern electrical and electronic systems.
Automatic AC/DC Detection
The testo 770-1 automatically recognises AC and DC voltage and current, eliminating manual selection errors and speeding up everyday workflows.
testo 770-1 Key Features:
- True RMS (TRMS) measurement for reliable accuracy
- Fully retractable pincer arm for maximum flexibility
- Automatic AC/DC measurement detection
- Large, backlit two-line LCD display
- Non-contact current measurement up to 400 A
- Inrush (starting) current measurement
- CAT IV 600 V / CAT III 1000 V safety rating
▶ See What the Testo 770 Can Really Do:
Typical Applications
The testo 770-1 Clamp is ideally suited for:
- Measuring current consumption
- Testing voltage supply on live conductors
- Measuring ionisation current in heating systems
- Continuity testing on switching components
- Resistance measurement of sensors and motor windings
Technical Specifications – testo 770-1 Clamp Meter
Electrical Measurement Data
| Parameter | Specification |
| DC Voltage – Measuring Range | 1.0 mV to 600.0 V |
| DC Voltage – Resolution | max. 0.1 mV |
| DC Voltage – Accuracy | ± (0.8 % of mv + 3 digits) |
| AC Voltage – Measuring Range | 1 mV to 600 V |
| AC Voltage – Resolution | max. 1 mV |
| AC Voltage – Accuracy | ± (1.0 % of mv + 3 digits) |
| DC Current – Measuring Range | 0.1 to 400 A |
| DC Current – Resolution | max. 0.1 A |
| DC Current – Accuracy | ± (2.0 % of mv + 5 digits) |
| AC Current – Measuring Range | 0.1 to 400 A |
| AC Current – Resolution | max. 0.1 A |
| AC Current – Accuracy | ± (2.0 % of mv + 5 digits) |
| Resistance – Measuring Range | 0.1 Ω to 40.00 MΩ |
| Resistance – Resolution | max. 0.1 Ω |
| Resistance – Accuracy | ± (1.5 % of mv + 3 digits) |
| Capacitance – Measuring Range | 0.01 nF to 100.0 µF |
| Capacitance – Resolution | max. 0.01 nF |
| Capacitance – Accuracy | ± (1.5 % of mv + 5 digits) |
Instrument Measurement Functions
| Features | |
| True RMS (TRMS) | ✓ |
| Inrush current measurement | ✓ |
| Automatic measurement parameter detection | ✓ |
| Continuity testing | ✓ |
| Diode test | ✓ |
| Min / Max | ✓ |
| Hold function | ✓ |
| Display backlighting | ✓ |
| Display resolution | 4,000 counts |
General Technical Data
| Specification | Details |
| Operating temperature | -10 to +50 °C |
| Storage temperature | -15 to +60 °C |
| Operating humidity | 0 to 80 %RH |
| Weight | 378 g |
| Dimensions | 249 × 96 × 44 mm |
| Display | 2-line LCD |
| Battery type | 3 × AAA micro batteries |
| Interface | 2 measuring jacks |
| Internal resistance | 11 MΩ (AC / DC) |
| Overvoltage category | CAT IV 600 V |
| Standards | EN 61326-1; EN 61010-2-032; EN 61140 |
| Authorisations | CSA; CE |
❓ Frequently Asked Questions (FAQ)
Q1: What makes the testo 770-1 different from a standard clamp meter?
A. The testo 770-1 features a unique retractable pincer arm and automatic parameter detection, making it safer and easier to use in tight switching cabinets compared to conventional clamp meters.
Q2: Does the testo 770-1 Clamp measure both AC and DC current?
A. Yes. The testo 770-1 Clamp automatically measures both AC and DC current and voltage.
Q3: Is the testo 770-1 suitable for daily professional use?
A. Absolutely. The testo 770-1 is the standard model in the 770 series and is designed specifically for everyday measuring tasks, including inrush current measurement.
Q4: Who is the testo 770-1 Clamp best suited for?
A. It’s ideal for electricians, HVAC engineers, maintenance technicians, and facilities professionals who need fast, accurate, and safe electrical measurements.