ESR2501C Capacitor ESR DCR Tester – In-Circuit LCD Meter
ESR2501C Capacitor ESR DCR Tester – In-Circuit LCD Meter
ESR2501C Capacitor ESR & DCR Tester — Precision In-Circuit Capacitance Meter
The ESR2501C is a professional-grade capacitor tester that accurately measures Equivalent Series Resistance (ESR) and DC Resistance (DCR) of electrolytic capacitors — both in-circuit and offline. Featuring a clear LCD display, auto-zero calibration, overvoltage protection, and smart auto-shutoff, this meter is an essential tool for electronics technicians, hobbyists, and engineers who demand reliable, repeatable results.
Made in Mainland China.
Key Features
- High-Precision Measurement: Dual measuring range — 0–5Ω (resolution: 0.01Ω) and 5–25Ω (resolution: 0.1Ω) — with automatic range switching for seamless testing.
- Industry-Standard 100 kHz Test Frequency: Measures ESR at the recognized 100 kHz standard frequency with a safe 5 mA measuring current, ensuring accurate, real-world results.
- True ESR via Synchronous Detection: Synchronous short-circuit detection technology ensures the displayed value reflects the true ESR of the capacitor, not interference from the surrounding circuit.
- ESR / DCR Mode Switching: Instantly toggle between ESR and DCR (DC resistance) measurement using the ON/OFF/ZERO button — ideal for comprehensive capacitor analysis.
- Automatic Zero Adjustment: Auto-zeroing activates at power-on and again each time you switch between ESR and DCR modes. The LCD simultaneously shows the ESR value and the probe compensation value so you can fine-tune zero for maximum accuracy.
- Temperature Compensation: Built-in temperature compensation enhances measurement stability across varying operating environments.
- Overvoltage Input Protection: Protects the meter's input circuitry from accidental voltage spikes during live-circuit testing.
- Smart Auto-Shutoff: Automatically powers down after ~5 minutes of inactivity to conserve battery life. Low-voltage detection triggers an LCD warning and shuts the unit off after 10 seconds.
- Rechargeable Battery Support: Uses a 3.7V 14500 lithium rechargeable battery (not included). Can be used while charging via DC 5–6V input. On-board charging indicator: red = charging, green = fully charged. Typical charge time: 2–3 hours. Max operating current: ~60 mA at 3.7V.
- User-Friendly Interface: Simple controls and a clear LCD make this meter accessible for beginners while delivering the accuracy demanded by professionals.
Specifications
| Measuring Range | 0–25Ω (auto-switching: 0–5Ω / 5–25Ω) |
| Resolution | 0.01Ω (0–5Ω range) / 0.1Ω (5–25Ω range) |
| Accuracy | ±1.5% ±0.01Ω (0–5Ω) / ±1.5% ±0.1Ω (5–25Ω) |
| Test Frequency | 100 kHz |
| Measuring Current | 5 mA |
| Display | LCD |
| Battery | 3.7V 14500 Li-ion rechargeable (not included) |
| Charging Input | DC 5–6V via USB |
| Product Dimensions | 125 × 80 × 32 mm / 4.92 × 3.15 × 1.26 in |
| Country of Origin | Mainland China |
What's in the Box
- 1 × ESR2501C Tester Unit
- 2 × Test Pens
- 2 × Test Clips
- 1 × USB Charging Cable
Note: Battery is not included. A 3.7V 14500 lithium rechargeable battery is required for operation.
For more information on electrical safety best practices when working with testing equipment, visit the OSHA Electrical Safety Guidelines.
Frequently Asked Questions
Q: Can the ESR2501C measure capacitors while they are still installed on a circuit board?
A: Yes. The ESR2501C supports both in-circuit and offline capacitor testing. Its synchronous detection method ensures the displayed ESR value reflects the true capacitor ESR, minimizing interference from surrounding components during in-circuit measurements.
Q: What type of battery does the ESR2501C require, and is it included?
A: The ESR2501C requires a 3.7V 14500 lithium rechargeable battery (similar in size to an AA battery). A battery is not included with the unit. The meter can be used while charging via a DC 5–6V USB power source, and the onboard LED indicates charging status (red = charging, green = full).
Q: What is the difference between ESR and DCR measurement on this meter?
A: ESR (Equivalent Series Resistance) is measured at 100 kHz AC and reflects the real-world resistive losses of a capacitor — a critical indicator of capacitor health. DCR (DC Resistance) measures the purely resistive component under DC conditions. The ESR2501C lets you switch between both modes using the ON/OFF/ZERO button, making it a versatile tool for thorough capacitor evaluation.
Q: How do I zero the ESR2501C for accurate readings?
A: The meter performs automatic zero adjustment every time it powers on and each time you switch between ESR and DCR modes. The LCD displays both the measured ESR value and the probe compensation value simultaneously, allowing you to monitor and fine-tune the zero adjustment manually if needed for the highest accuracy.