UNI-T UT211A/B Mini Digital Clamp Meter User's Guide

1. Basic Overview

The UT211 series mini digital clamp meter is a highly reliable and safe product. Features include automatic range, miniaturization, and the ability to accurately measure small current signals. The resolution can reach 0.1mA, and the product chip has a VFC (Variable Frequency Control) startup mode. It incorporates a specific filter circuit to filter out high-frequency interference signals, ensuring measurement accuracy. This makes it applicable to fields with VFC variable frequency voltage and current. Combined with full-range overload protection and a unique appearance design, it performs well as a new generation of practical electrician/power measuring instruments.

[Figure 1: Product Panel Diagram] A diagram illustrating the front panel of the clamp meter with numbered components: 1. Vise, 2. Pliers trigger (press to open jaws), 3. NCV Indicator Light (emits alarm sound and flashing light when sensing AC electric field), 4. Function selection knob (switchable between ACV/DCV/Hz, resistance, diode, capacitance, current ACA/DCA, NCV, OFF), 5. HOLD/backlight key (press for read lock, long press for ~2 seconds to activate backlight), 6. ZERO key (for DCA zeroing, capacitance/voltage relative value measurement), 7. SELECT key (select function mode), 8. LCD display (measurement function, symbol, numerical value display), 9. Positive input jack (for testing voltage/frequency, resistance/capacitance/diode, red probe insertion), COM end input jack (test voltage/frequency, resistance/capacitance/diode, black probe insertion).

2. Unpacking and Inspection

Open the package and take out the instrument. Please check carefully whether the following accessories are missing: User's Guide, 1.5V AAA battery, Qualification Certificate. If any items are missing or damaged, please contact your supplier.

3. Safety Instructions

This product design complies with IEC/EN61010-1, EN61010-2-30 safety standards. Read the operating instructions before use and follow all safety instructions:

1. Use the clamp meter according to the instructions in the operating manual; otherwise, the safety protection of the clamp meter may not function correctly.
2. Comply with national safety regulations and stay outside exposed energized conductors in hazardous areas. Personal protective equipment must be used to prevent injury from electric arc discharge.
3. Do not hold the current clamp anywhere other than the protective cover.
4. Before each use, check the insulation of the current clamp meter, housing, or output cable for cracks or defects, and check for any loose connections, especially around the clip mouth.
5. Before removing the battery cover, be sure to disconnect the clamp meter from all live circuits and remove the test leads.
6. Do not use where the voltage exceeds 600V (CATII 600V) or the frequency exceeds 400Hz.
7. Overvoltage category rating CATII 600V/CATIII 300V, pollution degree 2. Class III (CATIII) equipment is used to protect equipment in fixed installations, such as lightning protection devices in distribution boards, feeders, short branch circuits, and large buildings, from transient voltage damage.
8. Extreme caution should be exercised when working on bare wires, as contact with wires may result in electric shock.
9. For 60VDC (direct current), 30VAC (effective value of alternating current) or 42VAC (peak value of alternating current), extreme caution should be taken as such voltages pose a risk of electric shock.
10. This product has a maximum measurement voltage of 600V; safety regulations comply with CE/ETL certification (EN61010-1, EN61010-2-30, EN61010-2-32).

Fouelectrical symbols:

• [Battery Warning Symbol]: Insufficient battery inside the machine Warning.
• V: Voltage.
• AC/DC: AC/DC.
• [Double Insulation Symbol]: Double insulation.
• mA AC/DC: mA AC/DC.
• [Diode Symbol]: Diode.
• [Buzzer Symbol]: Buzzer on and off.
• [Ground Symbol]: Ground.
• ⚡: High voltage hazard.
• CE: Complies with European Union directives.

V. Comprehensive Specifications

The maximum voltage for protection against accidental operation between the input terminal and the ground is 600V. The maximum overload protection of the current clamp terminal is 100A (CE). Maximum display: 6000 Counts, updated 2-3 times per second. Overrange display: "OL".

[Figure 2: LCD full display image] A diagram illustrating the full LCD display of the clamp meter, showing various segments and symbols: 1. TRMS (True RMS Measurement Status Prompt), 2. AC/DC (AC/DC Voltage Measurement Prompt), 3. - (negative reading), 4. Diode (Diode measurement prompt), 5. - (Circuit continuity measurement prompt), 6. Data retention (Data retention prompt), 7. Ω, kHz, MHz (Resistance/Frequency units), 8. mV, V (Voltage units), 9. mA, A (Current units), 10. nF, µF, mF (Capacitance units), 11. NCV (Non-contact AC voltage sensing prompt), Auto (Auto range prompt), REL (Base zero/relative measurement prompt), ZERO (Frequency voltage/current measurement prompt), VFC (Low battery prompt in the machine), Low battery "?" (Automatic shutdown prompt).

[Figure II: Symbol Key] A key explaining the symbols displayed on the LCD: TRMS, AC/DC, -, Diode, -, Circuit continuity, Data retention, Ω, kHz, MHz, mV, V, mA, A, nF, µF, mF, NCV, Auto, REL, ZERO, VFC, Low battery "?", Automatic shutdown "?".

Full value of capacitor: 6200µF, frequency: 9999Hz. Diode: Approx. 3.2V. Range: Auto. Polarity: Automatic.

Working temperature: 0°C~40°C. Relative humidity: 0°C~30°C below ≤75%, 30°C~40°C ≤50%. Storage temperature: -10°C~50°C.

Electromagnetic Compatibility: Under a 1V/m RF field, the total accuracy = specified accuracy + 5%. No specifications are given for radio frequency fields exceeding 1 V/m.

Working altitude: 0~2000m. Internal battery: AAA 1.5V x2. Low battery: The LCD displays the "?" symbol.

Dimensions: Approx. (175×60×33.5)mm, Jaw opening maximum size 17mm. Weight: approximately 170g (including battery).

Safety standards: IEC/EN61010-1, EN61010-2-30; EN61010-2-32; CATIII 300V/CATII 600V; Pollution Degree 2. Certification: CE.

8. Operation Instructions

1. AC/DC Voltage/HZ Measurement

Select AC voltage, frequency (Hz) or DC voltage range and insert the red meter pen into the red hole (positive end), and the black meter pen into the black hole (COM port). Touch the red and black meter pens to the component under test, such as power outlets [Figure 3: Voltage measurement]. Read the measurement value from the LCD screen. When measuring voltage, the maximum input voltage value is 600V (AC/DC). Do not exceed this value; exceeding this limit risks electric shock or damage to the meter.

2. AC/DC Current Measurement

AC Current: Select the AC current range (600mA~, 6000mA~, 60A~). Open the clamp, hook the wire (single wire), and make sure the hook is completely closed with no gap. Read measurement data from the LCD. [Figure 5: AC/DC Current Measurement]

DC Current: Press the SELECT key to enter the DC current range (6000mA, 60A). Press the ZERO key to reset the reading to zero. If the reading is still not zero after pressing the key once, press it again. Zeroing is required due to the product's high sensitivity to ensure accuracy. The direction of the clamp head hook must be the same as the direction of the object being measured. Open the clamp and hook the wire (single wire), ensuring the hook is completely closed. Read measurement data from the LCD. [Figure 6: DC Current Measurement] Note: When measuring current, please remove the test pen to avoid electric shock.

3. NCV Non-Contact Electric Field Measurement

To detect the presence of AC voltage or electromagnetic fields in a space, use the meter's front end of the clamp close to the object to be measured for inductive detection. The inductive AC voltage is analog and approximately indicated. The display shows "EF" when voltage is above the critical voltage, and "-" otherwise. The buzzing sound indicates the intensity of the sensed electric field. When measuring NCV with a range switch, please remove the test leads to avoid electric shock. [Figure 7: NCV Measurement]

4. Other Functions

• HOLD/Backlight: Press and hold the HOLD key for about 2 seconds to activate the LCD backlight function.
• Automatic Shutdown: If the knob switch is not operated for about 15 minutes during measurement, the instrument will "automatically shut down" to save energy. Press any key to wake up the instrument from auto shutdown state. Turn the knob switch to OFF and then restart.
• Cancel Auto Shutdown: Press and hold the SELECT key while turning on the power in the OFF state; the buzzer will emit a continuous 5-tone prompt, indicating the auto-shutdown function has been canceled. After shutdown and restart, it will return to the auto-shutdown function.

IX. Technical Indicators

Accuracy: Guarantee period is 1 year. Ambient temperature: 23°C±5°C (73.4°F±9F). Relative temperature: ≤75%.

1. DC Voltage Measurement

Input impedance: 600mV range > 1GΩ, other ranges input impedance are all about 10MΩ. (There will be unstable digital display when the 600mV range is open circuit; the display will be stable after the load is connected.) Stable within ±1 character. Maximum input voltage: ±600V.

2. AC Voltage Measurement

Input impedance: approximately 10MΩ. Maximum input voltage: 600Vrms. Display true RMS value. Frequency response: 45~400Hz. The peak factor of the AC wave can reach 3.0 at 4000 counts. The non-sinusoidal wave is based on the crest factor to increase the error: a) Add 3% when the crest factor is between 1 and 2. b) Add 5% when the crest factor is 2~2.5. c) Add 7% when the crest factor is 2.5~3. Overload protection: 600V-PTC.

3. Resistance Measurement

Range: Measured value = Measured display value - Meter pen short-circuit value. Open circuit voltage: about 1V. Overload protection: 600V-PTC.

4. Circuit Continuity and Diode Measurement

Continuity: Resistance setting: >150Ω, buzzer silent; Circuit good conduction resistance set to: ≤150Ω, buzzer beeping continuously. Open circuit voltage: about 3.2V. Normal voltage value of silicon PN junction: About 0.5 to 0.8V. Overload protection: 600V-PTC.

5. Capacitance Measurement (suitable for power frequency applications)

Overload protection: 600V-PTC. It is recommended to use REL (UT211A) or ZERO (UT211B) to measure the capacitance of less than or equal to 1µF. Only the measurement mode can ensure the accuracy of the measurement.

6. ACV Frequency Measurement

Input amplitude: ≥ 10V (DC level is zero). Frequency ≥65KHz for reference only! Overload protection: 600V-PTC.

7. DC Current Measurement (UT211B only)

Overload protection: 100A.

8. AC Current Measurement

Display true RMS value. Frequency response: 45~400Hz. The exchange wave crest factor can reach 3.0 at 4000 counts, the dal wave is based on the crest factor to increase the error: a) Add 3% when the crest factor is 1~2. b) Add 5% when the crest factor is 2~2.5. c) Add 7% when the crest factor is 2.5~3. Overload protection: 100A.

X. Maintenance and Repair

Warning: Make sure the power is off before opening the meter cover; the meter pen has left the input port and the circuit under test.

1. General Maintenance and Repairs

Clean the instrument with a damp cloth and mild detergent. Do not use abrasives or solvents on the outer shell. If you find any abnormality in the instrument, you should stop using it immediately and send it for repair. When the instrument needs to be calibrated or repaired, please contact a qualified technician or designated maintenance department.

2. Replace the Battery [Figure 8: Battery Replacement]

When the LCD displays the "low voltage" prompt "?", it should be replaced immediately. Replace the built-in battery, otherwise it will affect the measurement accuracy. Battery specifications: AAA 1.5V x2.

Manufacturer Information

Youli Technology (China) Co., Ltd. (UNI-T)

Address: No. 6, Gongye North 1st Road, Development Zone, High-tech Industry, Songshan Lake, Dongguan, Guangdong Province, China

Tel: (86-769)85723888

Fax: (86-769) 85725888

Email: infosh@uni-trend.com.cn

Postal code: 523808

Instructions for Film Production Requirements

Version: REV. 0

DWH design: Wei Yingsuo

CHK Audit: [Signature]

APPRO. approve: [Signature]

MODEL: UT211A/B

model: User manual in Chinese

Part NO.: 110401104810X

Material number: 110401104810X

UNI-T Unitech Technology (China) Co., Ltd.

UNI-TREND TECHNOLOGY (CHINA) LIMITED