Digital voltmeter, a multi-purpose electronic measuring instruments, generally contain ammeter, voltmeter, the function such as ohmmeter, sometimes referred to as the maneuver, maneuver, Electrical multimeter, or three meters.
The digital multimeter has portable devices for basic fault diagnosis, as well as devices placed on the workbench, some with resolution up to seven or eight bits.
Digital multimeter dt9205a (DMM) is an electronic instrument used in electrical measurement.It can have many special functions, but the main function is to measure voltage, resistance and current, DMMS, as a modern multi-purpose electronic measuring instrument, is mainly used in the physical, electrical, electronic, and other areas of the measurement.
The resolution of the Professional digital multimeter
Resolution refers to the measurement results of a table.By understanding the resolution of a table, you can see if you can see small changes in the signal being measured.For example, if the Multimeter tester has a resolution of 1mV in the range of 4V, you can see a small change in 1mV (1/1000v) when measuring the 1V signal
If you're measuring less than a quarter of an inch (or a millimeter) in length, you're not going to use a minimum of an inch (or centimeter).If the temperature of 98.6 ° F, then a only integer tag thermometer is useless.You need a resolution of 0.1 ° F thermometer.
The bits and words are used to describe the resolution of the table.Multipurpose tables of Numbers are categorized by the number of digits and words they can display.
Measure the current
Current measurement is different from other measurements using a digital multimeter.The direct current measurement method is to connect the digital multimeter directly to the circuit under test, so that the current of the circuit under test can flow directly through the internal circuit of the multimeter.Indirect measurement does not require opening the circuit and stringing the multimeter onto the circuit under test.The indirect method USES a current clamp.
Direct current measurement
1. Turn off the circuit power
2. Disconnect or disassemble the welding circuit so as to string the watch into the circuit
3. Select the corresponding ac (A~) and dc (A--) stops
4. Insert the black stylus into the COM socket, and insert the red stylus into the 10-ampere jack (10A) or 300mA jack.The selection of that socket is based primarily on possible measurements.
5. Connect the stylus in series to the disconnected circuit.
6. Turn on the circuit power
7. Observe the readings and pay attention to the units.
Note: when measuring dc, if the test probe is connected backwards, "--" will appear.