Digital Multimeter Technical Features and How to Operate the Front Panel
The digital multimeter is a small digital multimeter with a three-and-a-half-digit LCD display. It can measure AC and DC voltage and AC and DC current, resistance, capacitance, transistor β value, diode conduction voltage and circuit short circuit, etc. The measurement function and range can be changed by a rotary band switch, with a total of 30 levels.
The maximum display value of this multimeter is ±1999. It can automatically display "0" and polarity. It displays "1" or "-1" when overloaded. When the battery voltage is too low, it displays the "←" mark and uses a buzzer for short circuit inspection.
Digital multimeter technical characteristics
1. Measuring range
⑴AC and DC voltage (AC frequency is 45Hz~500Hz);
The measuring ranges are 200mV, 2V, 20V and 1000 respectively. The DC accuracy is below ± (0.8% of the reading + 2 digits), and the AC accuracy is ± (1% of the reading + 5 digits);
Input impedance, DC range is 10MΩ, AC range is 10MΩ, 100PF.
⑵AC and DC current
The measuring ranges are 200μA, 2mA, 200mA and 10A respectively. The DC accuracy is ± (1.2% of the reading + 2 digits), the AC accuracy is ± (2.0% of the reading + 5 digits), and the maximum voltage load is 250mV (AC effective value) ).
⑶Resistance:
The measuring ranges are: 200Ω, 2kΩ, 200kΩ, 20MΩ and 20MΩ. Accuracy is ± (2.0% of reading + 3 digits).
⑷Diode conduction voltage:
The measuring range is 0~1.5V, and the test current is 1mA±0.5mA.
⑸ Transistor β value detection:
The test conditions are: VCE=2.8V, IB=10μA.
⑹Short circuit detection:
Test circuit resistance <20Ω±10Ω2. Sampling time: TS=0.4S.
Panel and operating instructions
1. monitor
Three and a half digit LCD display
2. switch
Press to turn on the power, and turn it off when not in use.
3. Capacitance measurement socket
When measuring capacitance, insert the capacitor pin into the socket.
4． Function range switch
Choose between different measurement functions and ranges.
5. 10A current jack (cannot measure current greater than 10A)
When measuring AC and DC currents greater than 200mA and less than 10A, the red test lead should be inserted into this 10A current jack.
6. Current jack
When measuring AC or DC current less than 200mA, the red test lead should be inserted into this current jack.
7． V/Ω jack
When measuring AC and DC voltage, resistance, diode conduction voltage and short circuit detection, the red test lead should be inserted into this V/Ω jack.
8. The black test lead of the ground common terminal "COM" jack is always inserted into this ground jack.
9. Beta value test socket
Insert the collector, base and emitter of the triode under test into the "C", "B" and "E" jacks respectively. Pay attention to distinguish whether the triode is NPN type or PNP type.
