With a current measurement, the electrical current is determined in an electrical circuit. The electric current, according to the International System of Units, is given in the unit of measure Ampere (A). Technical devices to measure the amperage are referred to an ammeter. A multimeter can take over this function. Current measurement using a multimeter is one of the three standard functions of the devices and can, therefore, be carried out with any model.
Measuring the current with the multimeter is also a relatively easy task, but you should pay attention to a few points so that the device is not damaged. Many inexperienced users permanently damage their multimeter due to incorrect settings when measuring current. The dangers of measuring the current are so great that, in contrast to other measuring processes such as measuring voltage or measuring resistance, the device itself must be switched into the circuit to be measured.
Different measuring ranges and connection sockets
The current can occur in different quantities. For example, it may be 200 milliamps or 20 amps. To be able to determine the correct value during current measurement with the multimeter, the device must be set to the appropriate measuring range. For simple models, the range is set manually using the central selection switch. Multimeter with auto-range function automatically detects the measuring range and adjusts itself.
Attention! The set measuring range must never be smaller than the expected current. If you measure a current of 20 A with the set up to a maximum of 200 mA, the device may be damaged. When setting the measuring range manually, they always start with the highest measuring range for unknown measured values and feel their way down in small steps so as not to overload the device by mistake.
Most devices have separate settings for microamps, milliamps, and amperes and higher currents. Good multimeters also have different sockets for different currents. Often there is a separate jack for the milliampere range and a separate jack for higher ampere areas. This helps to avoid gross misadjustments.
Procedure when measuring current with the multimeter
To be able to measure the correct number of amps with your device, follow the instructions below:
Step 1: Set the measuring range
First, set the multimeter to the appropriate range (mA, A, 10A, etc.). To do this, adjust the central selector switch so that the tip of the controller points to the corresponding inscription on edge.
Step 2: Unlock and open circuit
Now the circuit to be measured has to be opened at any point to be able to loop in the measuring device there afterward. Before doing so, it is important to turn off the power to the circuit.
Step 3: Apply test leads and close the circuit
The test leads of the multimeter are now looped into the circuit. The device itself is therefore used to close the circuit again. To do this, connect the black cable of the – pole to the COM socket and connect the red cable with the + pole to the INPUT socket for amps. If the supply voltage is reactivated, the current now flows directly through the device and can be measured in this way.
Step 4: Measure amps
On the display of the multimeter, the current in amperes can now be read directly.
General tips for measuring electricity with multimeters
The following notes should be noted when measuring current with a multimeter:
- Read the operating instructions of the multimeter carefully before measuring.
- Select the correct INPUT jack.
- Set the correct measuring range.
- Start with unknown measured values in the highest measuring range.
- Use safe measuring leads to suitable measuring tips.
- Use full batteries to eliminate measurement errors.
- After use, do not leave test leads in the socket for current measurement.
- After use, switch off the device or set it to the largest measuring range.
Before measuring the current with multimeters, you should deal exactly with your device. How is the measuring range set? Which socket should be used? How should the test leads be connected to the circuit? Only when one is familiar with the own model and has the operation under control, the current should start measuring.