Digital Multimeter ( HTC – DM-81 )

Description

The HTC DM‑81 Digital Multimeter is a compact yet powerful 3½‑digit handheld meter, offering precision measurement capabilities for both professional technicians and electronics hobbyists. Designed with True RMS measurement and a manual-range interface, it combines reliability and flexibility in a rugged form factor weighing just ~180–200 g, powered by two AA 1.5 V batteries.

Featuring overload protection across all ranges, the DM‑81 measures a wide spectrum of electrical parameters. It supports DC voltage up to 1000 V, with resolution from 0.1 mV to 1 V and accuracy of ±1.2% +5 digits (up to 200 mV/2 V/20 V) and ±1.5% +5 digits at 200 V/1000 V. AC voltage measurement reaches up to 750 V, with ±1.5% accuracy in low-voltage ranges and ±2% at 750 V, and resolution scaling accordingly.

Current measurement includes DC modes up to 20 A (unfused input) and 200 mA (fused with 200 mA/250 V fuse), with accuracies of ±1.5% (2 mA), ±2% (200 mA), and ±3% (10 A). AC current measurement scales similarly, with resolution as fine as 10 μA and accuracy up to ±3%.

Resistance measurement extends up to 200 MΩ, with five ranges (200 Ω to 200 MΩ), offering 0.1 Ω to 100 kΩ resolution, and accuracy ranging from ±1.5% to ±5% depending on range. Continuity testing sounds a buzzer under 50 Ω, while the diode test applies ~1 mA current.

Additional functionalities include capacitance measurement (20 nF to 200 μF), with resolutions from 10 pF to 10 nF and accuracy around ±4%. Frequency measurement up to 200 kHz is supported, with a resolution from 1 Hz to 0.1 kHz and accuracy up to ±1.5%. The meter also features transistor hFE testing (0–1000 β) and a built-in infrared remote control signal detector—able to sense IR transmissions from small distance.

The DM‑81 includes a crisp 1999-count LCD display for clear numerical visibility, complete with a continuity indicator, low battery alert, and auto-range selection warnings. It supports both live wire detection and IR remote control testing features for added convenience. The meter complies with IEC 61010‑1 CAT I standards for voltages up to 1000 V and offers full overload protection across ranges.

User convenience is enhanced by functions like Data Hold (freezing the display), auto power-off after ~15 minutes to conserve battery life, and low battery indication on display. Accessories include test leads, batteries, a protective holster, and a user manual—all included.

Operating reliably in ambient temperatures from 0 °C to 40 °C, and storage conditions from –10 °C to 50 °C, with humidity limits under 85%, the device remains accurate and durable under varied workplace conditions. The accuracy guarantee is based on conditions around 23 ± 5 °C and humidity <70%.

Compact and ergonomically designed (approx. 170 × 85 × 38 mm), the DM‑81 is easy to grip, carry, and operate for prolonged tasks. Its straightforward manual-range dial, intuitive button layout, and bright LCD make it ideal for educational labs, electrical maintenance, troubleshooting, and everyday measurement needs.

Key Highlights:

• Single 3½‑digit True RMS display (up to 1,999 counts)

• Comprehensive measurement: DC/AC voltage, DC/AC current, resistance, capacitance, frequency, diode, hFE, continuity, IR signal detection

• High voltage support: DC up to 1000 V, AC up to 750 V

• Wide current range: up to 20 A DC (10 A AC), with overload protection

• Solid resolution and accuracy across ranges

• Practical features: Data Hold, auto shut-off, low-battery alert, continuity buzzer

• Certified safety: IEC 61010‑1 CAT I compliance with full overload protection

• Portable design with accessories: leads, batteries, manual, protective sleeve

Recommended Use Cases:

• Electrical troubleshooting and maintenance in home or workshop

• School or vocational training labs for basic electronics

• HVAC fault diagnosis and live wire identification

• Consumer electronics servicing and repair

• Continuity and diode testing in circuits

With its reliable performance, intuitive interface, broad testing functions, and affordability, the HTC DM‑81 Digital Multimeter is a dependable tool for routine electrical diagnostics, educational use, and practical daily troubleshooting.