Overview
The Fluke 787B and Fluke 789 are both ProcessMeter™ models that combine a digital multimeter with a loop calibrator. They share rugged design, True-RMS measurement, and loop calibration capability, but there are key differences that matter in daily use.
Comparison Table
| Feature | Fluke 787B | Fluke 789 |
|---|---|---|
| Loop Power Supply | No | Yes, 24 V built-in |
| HART Mode | No | Yes, with 250 Ω resistor |
| SpanCheck Buttons | No | Yes, 0% / 100% quick calibration |
| Multimeter + Loop Calibrator | Yes | Yes |
| Safety Rating | CAT IV 600 V / CAT III 1000 V | CAT IV 600 V / CAT III 1000 V |
Shared Features
Both the 787B and 789 offer:
- Full-featured True-RMS digital multimeter.
- Measurement of AC/DC voltage, current, resistance, frequency, and continuity.
- Milliamp sourcing and simulation from 0–20 mA, with simultaneous display in mA and percent of span.
- Safety ratings of CAT IV 600 V / CAT III 1000 V.
- Data logging and functions like Min/Max/Average, hold, relative mode, and diode test.
Key Differences
Fluke 787B
- Provides DMM and loop calibration functions but does not have a built-in loop power supply.
- Requires an external power source to drive 4–20 mA loops.
- Best suited for general loop testing where external loop power is available.
Fluke 789
- Includes a built-in 24 V loop power supply, allowing standalone loop testing.
- Designed with HART mode support through a built-in 250 Ω resistor for working with smart transmitters.
- Features dedicated 0% and 100% SpanCheck buttons for fast calibration of 4–20 mA loops.
- Provides greater convenience for technicians handling advanced process instrumentation.
Which One Should You Choose?
Choose the Fluke 787B if you need a reliable combination of multimeter and loop calibrator, already have external loop power, or are looking for a more cost-effective option.
Choose the Fluke 789 if you often work with HART-enabled devices, prefer having built-in loop power, or want the convenience of SpanCheck buttons and an all-in-one tool.
Final Verdict
The Fluke 787B is a solid and reliable tool for basic loop testing, while the Fluke 789 provides enhanced functionality and convenience for technicians who need loop power and HART support. Both are durable, accurate, and designed to make process calibration tasks easier, but the right choice depends on your workflow and feature needs.