1、 Preparation before use

1. Check the integrity of the equipment
   • Confirm that the appearance of the instrument is not damaged (such as cracks in the display screen or deformation of the housing), and that the interfaces (such as probes and communication ports) are not loose or corroded.
   • Check battery level: If the battery level is below 20%, it is recommended to fully charge it before use to avoid abnormal data or automatic shutdown caused by low battery level.
   • Check accessories: Ensure that the test line, probe, sensor and other accessories are complete and the model matches (such as the range of the current clamp needs to cover the current to be measured).
2. Environmental adaptability confirmation
   • temperatureThe working temperature range is usually -10 ℃~50 ℃ (some models support -20 ℃~60 ℃). Exceeding this range may cause sensor drift or battery performance degradation.
   • humidityAvoid using in environments with humidity greater than 85% to prevent internal condensation and short circuits.
   • Dustproof and WaterproofIf the instrument protection level is IP67, it can be briefly immersed in water, but long-term exposure to dust or water mist should be avoided.
3. Safety protection measures
   • Wear insulated gloves and goggles, especially when operating in high voltage environments (such as CAT III 1000V).
   • Ensure that the insulation layer of the test line is intact and there are no exposed wires to prevent electric shock or short circuit.
   • Before using in flammable and explosive places (such as chemical workshops), confirm whether the instrument has explosion-proof certification (such as ATEX, IECEx).

2、 Precautions during operation

1. Correctly connect the test line
   • voltage measurementInsert the red test line into the "V Ω" hole and the black test line into the "COM" hole. When the probe contacts the measured point, keep it vertical to avoid sliding and causing a short circuit.
   • current measurement：
     • When using a clamp gauge, ensure that the jaws are closed and no debris enters to avoid errors caused by magnetic flux leakage.
     • The direct current meter needs to disconnect the circuit and connect the instrument in series, paying attention to polarity (red in and black out).
   • Resistance/on-off measurementDisconnect the power supply of the tested circuit to prevent interference from parallel components (such as residual charges in capacitors that may damage the instrument).
2. Range and mode selection
   • auto-rangingPriority should be given to enabling the automatic range function, but it is necessary to observe whether the instrument switch is smooth to avoid frequent jumps that may cause unstable readings.
   • manual rangeIf the range of the measured value is known, manually select a range slightly larger than the measured value (such as selecting 600V when measuring 220V voltage) to improve accuracy.
   • Mode SwitchBefore switching functions (such as voltage → current), the test line must be disconnected to prevent input overload.
3. Avoid interference and errors
   • electromagnetic interferenceStay away from strong radiation sources such as frequency converters and welding machines, or use shielded test wires to reduce noise.
   • Common mode voltageWhen measuring high side voltage (such as three-phase electricity L-N), ensure that the common mode rejection ratio (CMRR) of the instrument is greater than 60dB to prevent common mode signal interference.
   • temperature effectWhen measuring resistance, if the ambient temperature fluctuates by more than 5 ℃, wait for the instrument temperature to stabilize before reading.
4. Real time monitoring and alarm
   • Set a threshold alarm (such as a voltage upper limit of 240V), and the over limit instrument will emit a beep or flash prompt. The measurement should be stopped immediately and the circuit checked.
   • Observe the instrument status indicator light: if the "OVERLOAD" light is on, it indicates that the input has exceeded the limit and needs to switch to a higher range or reduce the signal strength.

3、 Data recording and communication

1. Data Storage Specification
   • Regularly clean the memory: If the instrument supports 100000 sets of data storage, it is recommended to export the data every week and format the internal storage to avoid overflow and loss of new data.
   • Label data: Record the measurement time, location, and object being measured during storage for subsequent analysis (such as "2024-03-01 Motor A-phase Voltage").
2. Wireless Communication Security
   • When connecting via Bluetooth/Wi Fi, enable password protection (such as WPA2) to prevent unauthorized devices from stealing data.
   • Avoid transmitting sensitive data on public networks (such as open Wi Fi) and prioritize using the instrument's built-in encryption protocol (such as AES-128).

4、 Post use maintenance

1. Cleaning and Storage
   • Wipe the instrument housing with a dry cloth and avoid using alcohol or solvents (which may corrode the plastic).
   • The test wire should be wound neatly to avoid excessive bending that may cause wire breakage. When storing, use the original storage bag.
   • When not in use for a long time, remove the battery (if removable) to prevent leakage and corrosion of the circuit.
2. Regular calibration and self inspection
   • calibration cycleIt is recommended to calibrate every 12 months or shorten the cycle according to the frequency of use (such as calibrating every 6 months for high-frequency usage scenarios).
   • Self checking methodAfter turning on, observe whether the display screen is displaying normally and test the known value (such as verifying the resistance measurement function with a standard resistor).
   • Repair standardIf there is a reading drift greater than ± 1%, frequent crashes, or physical damage, please contact an authorized repair center.

5、 Special scenario precautions

1. High voltage measurement (>600V)
   • Use a high-voltage probe (such as 1000:1 attenuation ratio) and confirm that the rated voltage of the probe is ≥ the measured value.
   • Maintain a safe distance during operation (e.g. CAT III 1000V must be ≥ 30cm) to avoid arc flashover.
2. harmonic analysis
   • When measuring non sinusoidal waveforms, ensure that the instrument supports true RMS (TRMS) measurement, otherwise harmonic components may cause readings to be lower.
   • The sampling rate should be ≥ twice the highest frequency of the measured signal (e.g. a 50Hz signal should have a sampling rate of ≥ 100Hz).
3. temperature measurement
   • When using infrared temperature measurement, keep the distance between the instrument and the object being measured ≤ 1 meter to avoid steam and dust blocking the sensor.
   • K-type thermocouples need to ensure that the joints are securely fastened to prevent poor contact from causing temperature fluctuations.

6、 Common errors and solutions