Choosing the right process meter can make a big difference in how efficiently you work with current loops and instrumentation. The Fluke 773 and Fluke 789 are two popular options, each designed for slightly different needs.
While the 773 excels at non-intrusive loop testing with its clamp design, the 789 stands out as an all-in-one powerhouse with built-in loop power and HART support. In this comparison, we’ll break down their key features, strengths, and ideal use cases to help you decide which one is the better fit for your workflow.
Fluke 773: The Loop Clamp Specialist
- Non-disruptive loop testing with the ability to measure 4–20 mA signals without breaking the loop, thanks to its clamp design.
- Adds DC voltage source and measure capability, enabling verification of power supplies and analog I/O devices.
- Portable and flexible, with a detachable clamp and extension cable for tight spaces, a dual backlit display, and a built-in spotlight.
- High accuracy and sensitivity, offering 0.2% accuracy with 0.01 mA resolution, and non-contact measurement up to 99.9 mA.
Bottom line: A go-to tool for live-loop diagnostics, especially where non-intrusive measurements are vital.
Fluke 789: The All-in-One Process Powerhouse
- Includes a built-in 24 V loop power supply to drive loops without external power.
- HART ready, with a built-in 250 Ω resistor for working with smart transmitters.
- SpanCheck buttons for fast and intuitive 0% and 100% calibration of 4–20 mA loops.
- Large dual display with enhanced backlighting for visibility in dim environments.
Bottom line: A comprehensive tool for calibration and power-loop maintenance, especially in HART and standalone loop scenarios.
Feature Comparison
| Feature | Fluke 773 (Clamp) | Fluke 789 (ProcessMeter) |
|---|---|---|
| Non-disruptive measurement | Yes | No |
| Built-in loop power | No | Yes (24 V) |
| HART communication support | No | Yes (250 Ω resistor) |
| SpanCheck buttons | No | Yes |
| Clamp design for tight spaces | Yes | No |
Which Tool Suits Your Workflow?
Choose the Fluke 773 if you need:
- Fast, non-intrusive measurement in live loops.
- Portability and flexibility with clamp testing.
- Simple voltage or loop source testing without built-in loop power.
Choose the Fluke 789 if you need:
- All-in-one loop sourcing, calibration, and power delivery.
- HART-compatible diagnostics for smart instrumentation.
- Quick, reliable span checks and better visibility.
Final Verdict
If your work emphasizes loop diagnostics in tight or live environments, the Fluke 773 shines. But if you seek full-feature versatility, HART compatibility, and streamlined calibration in one rugged tool, the Fluke 789 stands out.