Digital Multimeter 301BBattery-powered, digital multimeter with true rms measurement function and LCD counting display. A very good quality device, made of high-grade materials, it is an indispensable part of any service, automotive workshop, as well as a meter useful in every home. Multimeter equipped with automatic range determination, which makes testing easier and faster.The meter does not require turning the dial to select the function, according to the input voltage / current / resistance / current, the meter will automatically identify the measurement. It features high precision, high reliability, clear reading, overload protection function. It is powered by a 3.2 V / 200 mA lithium battery. The backlight can be turned on permanently or turned off automatically after 15 seconds. It can automatically identify DC voltage and AC voltage, AC and DC 10A current, resistance, no need to switch, you can also manually switch to measure capacitance, continuity test and other parameters, it is a tool with excellent performance.SafetyThe design of this series of instruments complies with the IEC1010 clause (safety standard promulgated by the International Electrotechnical Commission). Before use, please read the precautions.1. When measuring voltage, do not enter the limit voltage exceeding the effective value of DC 1000 V or AC 1000 V;2. Voltage below 36 V is the safe voltage;3. When changing the function and range, the measuring leads should leave the measuring point;4. Choose the appropriate function and range, be careful of improper operation. Although this series of instruments has a full-range protective function, for safety reasons, you should pay more attention to it;6. The safety symbol indicates that "" has dangerous voltage "", is grounded, and "" is double insulated."" The operator must read the operating instructions "," low voltage symbol ". Power key:Press this key for more than 2 seconds to turn the meter on or off.Features:Display mode: LCD display;Display: 5999 (5 5/6) digital automaticMeasurement method: A / D conversion with double integral;Sampling frequency: about 3 times per second;Overrange indicator: highest digit is "OL";Low voltage display: symbol "" appears;Operating environment: (0 ～ 40) ℃, relative humidity <80%;Power supply: 200 mhA lithium batteryInput and output power: 3.7 V / 2 ASize: 152 × 76 × 35 mm (length × width × height);Weight: approximately 180g (including battery)Functions:ACVDCAACAResistance / continuity / diode testCapacitanceFrequency HzNCVAll unit symbolsManual backlighting / auto offTrue RMS measurementTemperature （℃ / ℉）LED flashlight Auto scan DC voltage / AC voltage (DCV / ACV)Input impedance: 10 MΩ;Overload protection: peak of 1000 V DC or 750 V AC. The specific operations are as follows:1. Press and hold POWER for more than 2 seconds, the auto scan status "----" will be displayed after startup.2. Insert the black test lead into the "COM" socket and the red lead into the "V / Ω" socket; the test lead reliably contacts the test point.3. When the measurement voltage between the input ports "COM" and "VR" is greater than 0.6V, regardless of AC or DC voltage, the instrument will compare the DC component and AC component, take the larger component signal, and then according to the measurement The value is automatically switched between 6V / 60V / 1000V, and then the measured value is displayed on the LCD.Note:1) The input voltage must not exceed DC600V or AC600V if there is a risk of damage to the instrument circuit; for high voltage circuits, pay special attention to avoid electric shock;2) After all measurement operations, disconnect the test leads from the circuit under test.ResistanceInput impedance: 10 MΩ;Overload protection: peak 600V DC or 600V AC.The specific operations are as follows:1. The display, when turned on, shows the auto scan status "----".2. Insert the black test lead into the "COM" jack and the red lead into the "V / Ω" jack; the test lead reliably contacts the test point.3. If the measured resistance at both ends of the test lead is less than 50 Ω, the buzzer will emit a continuous sound. If you need a fast buzzer measurement, press the power button to switch to fast buzzer measurement.4. If the closed loop resistance is measured, the resistance at both ends of the measured resistance must be discharged, otherwise, if the loop voltage is greater than 0.6 V, the meter will mistakenly treat this as a voltage measurement and enter voltage measurement mode.5. Enter the resistance measurement value between the "COM" and "V / Ω" input ports, the meter will automatically switch between 600Ω / 6kΩ / 60kΩ 600kΩ / 6MΩ / 60MΩ according to the resistance measurement value, and then the measured value will be on the LCD On display.Note:1) When measuring low resistance, the test leads will bring internal resistance. To obtain accurate readings, you can first record the value of shorted test leads and subtract the value when the test leads are shorted from the measurement reading;2) When measuring resistance, all power to the circuit under test must be turned off, and all capacitors must be fully discharged to ensure correct measurement values Quick on-off test / capacitance measurementOverload protection: peak 1000 V DC or 750 V AC.1. The display when turned on shows the status of automatic scanning "----".2. Insert the black test lead into the "COM" socket and the red lead into the "V / Ω" socket; the test lead reliably contacts the test point.3. If you need quick on-off test / capacitance measurement, continuously turn on the "power" switch to switch to quick on-off test / capacitance measurement in the second cycle and select the corresponding measurement function according to your measurement needs. When measuring capacitance, the size of the measured capacitance will automatically select different ranges, display the measured value on the LCD display, and the capacitance measurement range is 10nF / 100nF / 1uF / 10uF / 100uF / 1mF / 10mF / 100mF。Note:1) When measuring capacitance with 10nF, there may be residual readings on the value displayed on the screen. This number is the dissipated capacitance of the test pen. This is an accurate reading. You can subtract this value after the measurement;2) When measuring large capacitance files with serious leakage or puncture capacitance, some values will be displayed and unstable; when measuring large capacitance, the reading will stabilize after a few seconds, which is normal when measuring large capacitance;3) Before checking the capacitance of a capacitor, it must be completely discharged, otherwise it will go into voltage measurement mode.4) Unit: 1F = 1000mF 1mF = 1000uF 1uF = 1000nF 1nF = 1000pF AC and DC current (DC / ACV A)Maximum measured voltage drop: 600mV; overload protection: 10AThe specific operations are as follows:1. The display when turned on shows the auto scan status "----".2. Insert the black test lead into the "COM" socket and the red lead into the "10A" socket; the test lead reliably contacts the test point.3. When a current of more than 20 mA is inserted between "COM" and "10 A", the meter will display the LCD on the LCD according to the AC and DC components.Note:1) Before connecting the instrument in series with the circuit under test, turn off the circuit voltage;2) The maximum input current is 10 A (depending on the insertion position of the red test lead). Excessive current will damage the 10A fuse. Be careful not to use more than 10 seconds for each measurement, excessive current will cause the circuit to heat up or even damage the instrument;3) When the test lead is inserted into the current input port, do not connect the test lead of the test cable to any circuit in parallel, this will damage the fuse and the instrument5) After all measurement operations, turn off the power, and then disconnect the test leads from the circuit under test, which is more important when measuring large currents.6) It is forbidden to introduce voltages higher than 36 V DC and 25 V AC between the current socket and the "COM" socket. Measurement of NCV:Operation is as follows:1 Press and hold the "NCV" key; enter the EF measurement.2. There is an NCV test point on the front of the instrument. As long as the point is close to the AC voltage, the buzzer will emit different continuous tones according to different signal strengths. At the same time, the LCD displayDepending on the signal strength, the number of different segments will also be displayed. Included:Digital 301B multimeter with built-in battery2 x probe cablesTemperature measuring cableUSB cable for charging the device.