MESR-100 ESR Capacitor Tester – Auto-Ranging Low Ohm Meter
MESR-100 ESR Capacitor Tester – Auto-Ranging Low Ohm Meter
MESR-100 Professional ESR Capacitor & Low-Ohm Meter
The MESR-100 is a precision auto-ranging capacitor ESR (Equivalent Series Resistance) and low-ohm meter designed for electronics technicians, hobbyists, and repair professionals. Using a true 100 kHz sine-wave test signal, it measures capacitor internal resistance the same way capacitor manufacturers do — giving you accurate, reliable results fast.
With in-circuit testing capability, you can check capacitors directly on the board without desoldering, making it indispensable when troubleshooting TVs, LCD monitors, audio amplifiers, and other electronic equipment. A handy printed reference table is included right on the unit for instant pass/fail assessment.
Key Features
- Auto-Ranging: Measurement range from 0.001 Ω to 100.0 Ω — no manual range selection needed
- True 100 kHz Sine-Wave Signal: Cancels capacitive impedance for a pure ESR reading that matches factory test methods
- In-Circuit Testing: Applies less than 15 mV DC peak-to-peak, keeping capacitors safe while they remain on the board
- 4-Digit High Resolution: Reads down to 0.001 Ω in the 0–1 Ω range
- Dual Test Clips: Fast, easy connection to capacitor leads for quick inspection
- Flexible Power Options: Runs on 2 × AA batteries (not included) for over 80 hours of use, or via 5 V Micro-USB
- Compact & Lightweight: Approx. 14.5 × 8 × 3 cm / 139.6 g — easy to handle on the bench or in the field
- Built-In Reference Table: Printed directly on the unit for instant ESR range verification
Measurement Accuracy
| Range | Accuracy | Refresh Time (Manual) |
|---|---|---|
| 0.000 – 1.000 Ω | 1% + 2 Digit | ~0.4 s |
| 1.000 – 10.00 Ω | 1% + 1 Digit | ~0.4 s |
| 10.00 – 100.0 Ω | 2% + 1 Digit | ~0.4 s |
Auto mode: 0–2 s (additional time may be needed depending on capacitance value).
Specifications
- Color: Black
- Measurement Range: 0.001 Ω – 100.0 Ω
- Wide Range Support: Capacitors >1 µF
- Resolution: 4-digit / 0.001 Ω @ 1 Ω range
- Test Voltage: <15 mV DC (peak-to-peak)
- Power Supply: 5 V Micro-USB or 2 × AA 1.5 V batteries (not included)
- Operating Current: 0.02 A
- Battery Life: >80 hours
- Item Size: Approx. 14.5 × 8 × 3 cm (5.7 × 3.1 × 1.2 in)
- Item Weight: Approx. 139.6 g (4.9 oz)
- Country of Origin: Made in Mainland China
What's in the Box
- 1 × MESR-100 Capacitor ESR Meter
- 2 × Test Clips
- 1 × User Manual
Note: Batteries are NOT included. This meter tests capacitor internal resistance (ESR), not capacitance value.
You May Also Like
- Screw Extractor Drill Bit Set 5 & 6 Pc – Carbon Steel
- Adjustable Label Roll Holder – 3D Printed Thermal Printer Stand
Learn more: OSHA on personal protective equipment
Frequently Asked Questions
Q: What does the MESR-100 ESR meter actually measure?
A: The MESR-100 measures the Equivalent Series Resistance (ESR) of capacitors — the internal resistance found in series within a capacitor. A high ESR reading often indicates a failing or degraded capacitor even when its capacitance value appears normal. This makes the MESR-100 extremely valuable for diagnosing faults in TVs, monitors, audio boards, and other electronics.
Q: Can I test capacitors while they are still on the circuit board?
A: Yes! The MESR-100 supports in-circuit testing. It applies less than 15 mV DC peak-to-peak, which is low enough not to affect other components on the board. This allows you to quickly test capacitors without the time-consuming process of desoldering each one.
Q: What power source does the MESR-100 use?
A: The meter supports two power options: 2 × AA 1.5 V batteries (not included) offering over 80 hours of use, or a 5 V Micro-USB cable for bench work. This flexibility makes it suitable for both field repairs and workshop use.
Q: Is the MESR-100 suitable for beginners?
A: Absolutely. The auto-ranging function eliminates the need to manually select measurement ranges, and the built-in printed reference table on the unit helps you quickly interpret readings. The included test clips and user manual make setup straightforward even for those new to ESR testing.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.