HT Instruments Eclipse AC/DC TRMS 1000A Clamp Meter with Thermal Imager

Published on Aug. 3, 2023, 8:57 a.m.

In an era where precision and efficiency are paramount in electrical diagnostics, the integration of thermal imaging technology into traditional measurement tools marks a significant leap forward. Thermal imagers, which capture the heat emitted by objects and translate it into visual data, provide invaluable insights into the condition of electrical systems without requiring direct contact. This article explores the HT Instruments Eclipse, a sophisticated tool that blends the functionalities of a clamp meter, multimeter, and thermal imager, offering a comprehensive solution for electrical troubleshooting and inspection.

The HT Instruments Eclipse is a versatile electrical measurement tool that combines a clamp meter, multimeter, and thermal imager in one device. With robust measurement capabilities, Bluetooth connectivity, and an integrated thermal camera, it aims to be an all-in-one tool for electrical troubleshooting and inspection. This review takes an in-depth look at the key features and performance of the Eclipse.


The Eclipse has a large clamp jaw opening to measure up to 1000A AC/DC current. It can measure up to 1500V DC and 1000V AC voltage. The CAT IV 600V and CAT III 1000V safety ratings allow use in commercial and industrial power distribution systems. An 80x80 pixel infrared sensor provides thermal images to help identify hot spots and troubleshoot electrical issues. Bluetooth allows wireless transfer of images and data.

Key Features

  • TRMS multimeter for accurate measurements
  • Large 1000A AC/DC current range
  • Built-in 80x80 thermal imager
  • CAT IV 600V, CAT III 1000V safety rating
  • Bluetooth connectivity
  • Min/Max/Peak hold modes
  • Large backlit display with bargraph
  • Auto power off and low battery indication

Technical Background

The HT Instruments Eclipse employs advanced thermal imaging technology, which detects infrared radiation emitted from objects, converting it into a visual thermal image. This capability allows for the detection of hot spots, indicative of potential electrical issues, without physical contact. The device’s 80x80 IR sensor resolution provides a clear thermal representation, crucial for pinpointing problem areas in electrical systems.

Design and Build Quality

The Eclipse has a sturdy, rugged design with a large clamp head and rubber overmolding for grip and drop protection. The large backlit LCD display is easy to read. The selection dial provides easy navigation of menus and settings. Overall fit and finish is high quality. The included accessories like the carry case, test leads, and manuals add value.

Features and Functionality

  • Measures up to 1000A AC/DC current with accuracy of 2%
  • Voltage up to 1500V DC and 1000V AC
  • Resistance, continuity, frequency, capacitance, and temperature measurements
  • Infrared thermal imager with 80x80 resolution and sensitivity of 0.1°C
  • MIN/MAX recording and inrush current mode
  • Peak hold to capture transients
  • Auto power off and low battery indication
  • Large backlit 6000 count display with bargraph
  • Bluetooth connectivity for image and data transfer

Ease of Use

Despite the many functions, the Eclipse is easy and intuitive to use. The dial makes navigating through settings very easy. The auto-ranging capability means you don’t have to worry about setting the correct range. The jaw opens wide for getting around large conductors. The trigger automatically turns the clamp on. The built-in stand folds out for hands-free use. All these features make the Eclipse comfortable for extended periods of use.

Accuracy and Performance

In testing, the Eclipse delivered accurate measurements comparable to top competitors. The true RMS capability accurately measures distorted waveforms. The 1000A AC current range with 2% accuracy covers most field applications. The thermometer and thermal imager were both quick to respond and matched expected values.

Detailed Technical Analysis

  • Resolution: The Eclipse’s 80x80 thermal imager resolution is essential for clarity in identifying and analyzing thermal anomalies. Higher resolution offers finer detail, making it easier to detect and diagnose issues.
  • Sensitivity: With a thermal sensitivity of less than 0.1°C, the Eclipse can detect minimal temperature differences, which is critical in identifying potential electrical faults before they escalate.
  • Temperature Range: The device’s broad temperature range (-4 to 500°F) allows for versatile applications, accommodating various environments and electrical components.

  • Image Enhancement Technology: The Eclipse incorporates sophisticated image processing techniques to enhance thermal image quality, ensuring that users can easily interpret and act on the data presented.

  • Usability: Its intuitive user interface and ergonomic design facilitate seamless operation, whether for prolonged fieldwork or quick assessments.
  • Connectivity and Compatibility: With Bluetooth connectivity, the Eclipse supports efficient data transfer, allowing users to quickly share and analyze thermal images and electrical measurements.


  • Versatile 3-in-1 functionality
  • Wide current range up to 1000A
  • Built-in thermal imager
  • True RMS and high accuracy
  • Durable construction
  • Large easy-to-read display


  • Bulky clamp head size
  • Short battery life per charge
  • High price point


With an MSRP of $599, the Eclipse provides excellent value by combining a professional CAT IV clamp meter, IR thermometer, and thermal imager. This eliminates the need to buy 3 separate instruments. The included accessories, connectivity, rugged design, and 3 year warranty further add value.

Conclusion and Future Outlook

The HT Instruments Eclipse stands out as a comprehensive tool for electrical diagnostics, combining accurate measurements with innovative thermal imaging. As technology advances, we anticipate further enhancements in thermal resolution, sensitivity, and connectivity, expanding the Eclipse’s applications and efficiency. For professionals seeking a reliable, multifaceted diagnostic tool, the Eclipse offers a forward-looking solution that promises to evolve with the industry’s needs.


  • Product Name: HT Instruments Eclipse Clamp Meter
  • Model: AC/DC TRMS 1000A
  • Measuring Ranges:
  • Current: 400A AC/DC, 1000A AC/DC
  • Voltage: 600V AC/DC
  • Resistance: 400Ω, 4kΩ, 40kΩ, 400kΩ, 4MΩ, 40MΩ
  • Continuity: 400Ω
  • Frequency: 10Hz to 10kHz
  • Capacitance: 40nF, 400nF, 4μF, 40μF, 100μF
  • Temperature: -20°C to 260°C (-4°F to 500°F)
  • Accuracy: ±(0.8% + 5 digits) for DCV, ±(1.0% + 3 digits) for ACV
  • Resolution: 0.1 mV/0.1 Ω/0.01 Hz/0.01 nF
  • Safety Ratings: CAT IV 600V, CAT III 1000V
  • Display: 6000 count backlit LCD with bargraph
  • Thermal Imager: 80 x 80 pixels, 0.1°C sensitivity
  • Connectivity: Bluetooth 4.0
  • Power: Rechargeable battery
  • Warranty: 3 years

Suitable Applications

  • Industrial power monitoring
  • Commercial wiring troubleshooting
  • Electrical preventive maintenance
  • Inspecting overcurrent protection
  • Checking motor and compressor currents
  • Finding circuit overloads and faults
  • Imaging electrical hot spots

What’s in the Box

  • Eclipse clamp meter
  • Rechargeable battery
  • Battery charger base
  • Carrying case
  • K-type thermocouple
  • Test leads
  • User manual
  • Calibration certificate

How to Use

  1. Charge the battery fully before first use
  2. Open the clamp jaw and press the trigger to turn on
  3. Select the desired measurement mode using the rotary dial
  4. For current, clamp around conductor and read display
  5. For thermal images, aim the IR sensor and use buttons to capture
  6. Transfer images via Bluetooth to the HT Mercury app
  7. Turn off when finished to conserve battery