How to Use a Few Resistors to Improve the Accuracy of a Multimeter
To improve the accuracy of your multimeter, you can use a few resistors and components. They should be held in place so that they stay in contact with the multimeter’s probes. Do not touch the resistors or components with your hands, as this will result in inaccurate readings. To avoid this problem, attach the components to a breadboard or use alligator clips to keep them in place.
Using shunt resistors
The resistance value of a shunt resistor is expressed in microOhms. The resistance of a shunt resistor is usually very small. Using this type of resistor improves the accuracy of the multimeter because it does not introduce undesired effects from lead resistance. It is important to use it with a Kelvin connection, however, because the resistance of shunt resistors tends to drift with the ambient temperature.
Multimeters are sensitive to load voltage, so operators must be vigilant about the burden voltage and resolution. Infrequent testing can result in unexpected product failures. Shunt resistors improve the accuracy of the multimeter by providing additional resolution. This is particularly useful for bench multimeters, which are capable of full-scale measurements.
Setting the correct range on an analog multimeter
To set the correct range on an analog multimeter, start by setting the ohms unit to its lowest value. In general, the resistance reading should be between 860 and 880 ohms. Alternatively, you can use the lower resistance range of 200 ohms for learning and practice.
A manual-ranging multimeter features a knob with many selection options. These are usually marked with metric prefixes. Auto-ranging multimeters, on the other hand, are automatically set to the appropriate range. In addition, they have a special “Logic” test function to measure digital circuits. For this function, you connect the red (+) lead to the anode and the black (-) lead to the cathode.
It may seem daunting to set the range on an analog multimeter, especially if you’ve never used one before. However, this task is surprisingly simple and can be done with a few resistors. As long as you’re aware of the different ranges, you’ll be more successful with this task.
Using precision current sensing resistors
The accuracy of a multimeter can be improved by using precision current sensing resistors. These components can be purchased in different styles. They are useful for applications where the correct amount of current entering and leaving a battery is necessary. They are also helpful for applications where temperature sensitivity is a concern.
The optimum footprint is C, with an expected measurement error of 1%. Recommended footprint dimensions are shown in Figure 6. The routing of the sensor trace also plays an important role in determining measurement accuracy. The highest accuracy is achieved when the sense voltage is measured at the resistor’s edge.
A current-sensing resistor is a low-value resistor that detects the flow of current and converts it to a voltage output. It is usually very low in resistance and therefore minimizes power loss and voltage drop. Its resistance value is usually on the milliohm scale. This type of resistor is similar to standard electrical resistors, but it is designed to measure the current in real time.
Touching the resistor or probe with your fingers
Multimeters also have a special feature that detects the positive and negative leads on a battery or power supply. Holding the multimeter probe against the lead for a few seconds will allow you to determine whether the current flowing through it is positive or negative. The red probe is connected to the positive battery terminal or wire.
When using a multimeter to measure resistance, you should make sure that the circuit is not powered on. Otherwise, you may receive an inaccurate reading. Remember that resistance is not as important as knowing how to measure it. Moreover, the current flowing in the circuit may damage the multimeter.
Testing continuity between holes on a breadboard
Before you measure resistance between holes on a breadboard, you should first check the breadboard’s connectivity. The test method is known as continuity check, and is a simple way to determine whether two connections are compatible. The breadboard has holes with a metal spring clip beneath each one. Connect the probes of your multimeter to both of these points. If you’re having trouble finding a conductive path between these points, attach a few resistors between the breadboard and the multimeter.
If you’re using a multimeter with a programmable feature, you can make it more accurate by testing continuity between a few holes at a time. To do this, insert the probes in the “+” and “-” columns of the breadboard and then measure the resistance across them. If the resistance is infinite, then the two rows are not connected.