Fluke 45 Multimeter
Manufacturers
Fluke
Other Recommendations
5.5-Digit Dual-Display Benchtop Multimeter with 0.05% DC Current Accuracy, True RMS Measurement, and 4-20mA Current Loop Diagnostics
📊 5.5-Digit
100,000-count resolution, 0.05% DC current accuracy (Source: Specifications)
🖥️ Dual Display
Simultaneous multi-parameter display (Source: Features)
🔧 Multifunctional
Voltage/current/resistance/frequency/dB/audio power (Source: Features)
| Core Parameter | Specification | Application Value |
|---|---|---|
| Measurement Accuracy | 5.5-digit resolution (100,000 counts), 0.05% DC current accuracy | Precision current loop testing (e.g., 4-20mA industrial loops) with ≤0.01mA error |
| Functional Coverage | True RMS AC/DC voltage/current, resistance (2Ω-8kΩ), frequency (up to 1MHz), dB, audio power | Replaces multiple instruments, ideal for lab/production line setups |
| Automation Support | RS-232 interface (GPIB optional), QuickStart 45 software package | Reduces test program development time by 50% |
Core Application Scenarios
Industrial Current Loop Diagnostics - 0.05% DC accuracy for precise 4-20mA signal measurement (error ≤0.01mA)
Electronics Production Testing - Dual displays monitor voltage/current simultaneously with PASS/FAIL indicators
Audio Equipment Debugging - Measures audio power (2W/16W) and dB with selectable reference impedance
Technical Architecture
Precision Measurement Architecture
Features "5.5-digit ADC + True RMS Conversion + Dual-Display Interaction": 24-bit ADC enables 100,000-count resolution. True RMS converter supports AC/DC measurements up to 1kHz bandwidth (0.1% accuracy). Vacuum fluorescent dual displays (main 5.5-digit/secondary 4-digit) enable simultaneous measurement/reference value comparison. LED indicators provide instant PASS/FAIL judgment (<100ms response). RS-232/GPIB interfaces support 100 samples/sec automation.
| Technical Dimension | Fluke 45 | Standard 4.5-Digit DMM | Advantage |
|---|---|---|---|
| Test Efficiency | Dual display + comparator (<1 sec/test) | Single display + manual check (>5 sec/test) | 400% faster throughput (5,000 units/day) |
| Current Loop Accuracy | 0.05% DC accuracy (error ≤0.01mA) | ≥0.1% accuracy (error >0.02mA) | 99.9% calibration pass rate |
4-20mA Current Loop Diagnostic Workflow
Connection: Series connection to current loop (sensor→PLC), DC current mode (20mA range), dual display active
Configuration: Enable 5.5-digit resolution, set comparator limits (high:21mA/low:19mA)
Diagnostics:
- Full-scale test: 19.8mA→PASS / 21.5mA→sensor drift
- Open-circuit: <4mA (e.g., 0.2mA)→wiring fault
- Short-circuit: >20mA (e.g., 25mA)→load shortReporting: Generate current-temperature correlation table with fault annotations
Usage Notes
1. Preheat 30 minutes for high-accuracy measurements (23±5°C ambient)
2. Always connect in series for current measurements (20mA range for 4-20mA loops)
3. Use shielded cables (≤5m) for RS-232 automation to prevent EMI
