Multimeter Ranges

The Definitive Guide To Using Multimeters

All multimeters come with different measurement ranges to accommodate a wide range of values that you might encounter when working with electronic components and circuits. These ranges are selectable on the multimeter itself before performing the measurement.

The addition of ranges is to accommodate for accuracy, sensitivity, protection, resolution, avoiding overload and speed of measurement.

the Definitive Guide to Using Multimeters

This is the 11th article in our series, The Definitive Guide to Using Multimeters.

This article delves into the multimeter ranges, why they are important and what the common ranges for multimeters are. We will also touch on auto-ranging multimeters and their importance.

If you missed the start of the series: What Is a Multimeter: The Definitive Guide to Multimeters, check it out now! You will be able to work your way back to this article quite quickly.

The Definitive Guide to Multimeters

• What is a Multimeter?
• Why Are Multimeters Important?
• What Do Multimeters Measure?
• What is the History of the Multimeter?
• What are the Common Types of Multimeters?
• What are Common Multimeter Options?
• What are Some Multimeter Specifications?
• What are Common Uses of Multimeters?
• How Do I Choose the Best Multimeter For The Job?
• How Do I Use a Multimeter?
• How Do I Properly Maintain a Multimeter?
• How Do I Calibrate a Multimeter?
• What is the Future of Multimeters?
• Multimeter FAQs

Why Are Multimeter Ranges Important?

Simply put, just because a multimeter can measure voltage, does not mean you can hook it up and start measuring voltages on a massive scale (say 10,000 volts) blindly. They just cannot be manufactured in a way that will safely cover all ranges that could ever possibly come up.

Because of this, multimeters have different measurement ranges to optimize the measurement that is about to be performed. This is done to ensure numerous things within the measurement:

Precision and Accuracy

Each measurement range of a multimeter is optimized for a specific range of values. This specialization enhances the precision and accuracy of measurements. When measuring smaller values, a finer scale is used, allowing for more detailed readings. Conversely, when measuring larger values, a coarser scale is employed to prevent overload and to maintain accuracy.

Sensitivity

Different measurement components within the multimeter, like resistors and amplifiers, are designed to handle specific ranges of values. For instance, to measure small currents or voltages accurately, the components must be sensitive enough to register those values without overwhelming the internal circuits.

Protection from Overload

Multimeters are designed to protect both the device and the user from potential harm. If you attempt to measure a value that is too high for the selected range, it could damage the multimeter or pose a risk to you. Having multiple ranges allows you to select the appropriate one for your measurement, reducing the chances of overload.

Resolution

Each measurement range is associated with a specific resolution, which is the smallest change in value that the multimeter can detect. Higher measurement ranges typically offer lower resolution, making them suitable for measuring larger values where fine details are less critical.

Speed of Measurement

In some cases, using a specific range might result in faster measurements. For example, on the highest resistance range, the multimeter's internal circuitry can measure resistance more quickly, while using a lower range might require more time for accurate readings.

What Are Common Multimeter Ranges?

Most multimeters are manufactured to cover the most common ranges of electrical measurements being performed. Common ranges for multimeters are as follows:

Voltage (AC and DC) Multimeter Ranges

• Low Voltage Range: Typically covers 200 millivolts (mV) or lower, suitable for sensitive voltage measurements.
• Standard Voltage Range: Covers several voltage ranges, such as 2 volts (V), 20V, 200V, and 1000V (also known as 1 kilovolt or 1kV), allowing for measurements in different voltage levels.

Current (AC and DC) Multimeter Ranges

• Microampere Range: Measured in microamperes (µA), usually ranging from a few microamps to 200µA or higher, suitable for low-current measurements.
• Milliampere Range: Measured in milliamperes (mA), covering ranges like 200mA or higher, for medium-level current measurements.
• Ampere Range: Measured in amperes (A), typically ranging from 2A to 10A or higher, for higher current measurements.

Resistance Multimeter Ranges

• Low Resistance Range: Covers measurements in the milliohm range, usually starting from a few milliohms to 200 milliohms or higher, for low-resistance measurements.
• Standard Resistance Range: Ranges like 200 ohms, 2 kilohms (kΩ), 20kΩ, 200kΩ, 2 megohms (MΩ), and higher, for general resistance measurements.
• High Resistance Range: Covers measurements in the megohm and gigaohm ranges, suitable for high-resistance measurements.

Capacitance Multimeter Ranges

• Typically covers ranges like picofarads (pF), nanofarads (nF), and microfarads (µF), allowing measurements of various capacitive values.

Frequency Multimeter Ranges

• Common frequency ranges include hertz (Hz), kilohertz (kHz), and megahertz (MHz), enabling frequency measurements in different ranges.

Temperature Multimeter Ranges

• Temperature ranges often include Celsius (°C) and Fahrenheit (°F) scales, covering a wide range of temperatures.

Multimeter Ranges and Resolution

Multimeter ranges and resolution are closely interrelated in the context of measurement precision and the ability to discern small changes in the measured value.

As we learned earlier, multimeter resolution refers to the smallest increment of change that a multimeter can detect and display on its screen. Higher resolution means the multimeter can display smaller changes in the measured value.

There's a trade-off between having a wide measurement range and having high resolution. A wide range is useful for measuring a broad spectrum of values, but it might sacrifice the ability to detect small changes within that range. When you choose a range, you're effectively determining the overall span of values that the multimeter can display.

For multimeters, a wider range typically comes with lower resolution, while a narrower range offers higher resolution. This affects the precision with which you can read and interpret the measurement.

A sample example of this would be something like the following:

Auto-Ranging Multimeters

While selecting the appropriate range for multimeter is critical for all the reasons mentioned above, the good news is that many newer multimeters come with an already built-in protection:  auto-ranging.

The auto-ranging feature of multimeters will automatically select the correct range once it is connected to a circuit.

The process of multimeter auto-ranging happens quickly, but there might be a slight delay as the multimeter determines the appropriate range and updates the display. However, this delay is usually minimal and doesn't significantly affect the measurement process.

We went over this in great detail in a previous post, .... But to let's recap some of those items here.

Benefits of Multimeter Auto Range

The primary benefit of this functionality is that it will simplify the measurement process, especially for beginners who might be uncertain about which range to select manually.

Additionally, auto-ranging multimeters will save you time by eliminating the need to manually adjust the range for each measurement.

It also helps you prevent measurement errors caused by selecting an inappropriate range.

Finally, you are far less likely to encounter overload situations, as the multimeter automatically adjusts to the best range.

How Multimeter Auto Range Works

Here's a detailed explanation of how multimeter auto-ranging functions work

1. Detection of Initial Value

When you connect the probes of the multimeter to the circuit or component you want to measure, the multimeter first detects the initial value of the parameter (voltage, current, resistance, etc.).

2. Analysis of Value Magnitude

Once the initial value is detected, the multimeter's internal circuitry analyzes the magnitude of the value. It determines whether the value falls within the range of a particular measurement setting (e.g., voltage ranges like 2V, 20V, 200V, etc.).

3. Selection of Appropriate Range

Based on the analysis, the multimeter's microcontroller or processor selects the measurement range that will provide the best accuracy and resolution for the detected value. If the value is relatively small, it will choose a higher range with finer resolution. If the value is larger, it will select a lower range for better precision.

4. Display Update

After the appropriate range is selected, the multimeter updates its display to show the measured value along with the selected range. The display might also indicate that the multimeter is in auto-ranging mode.

5. Adaptive Adjustment

As the measured value changes (for example, due to variations in the circuit or component being measured), the multimeter continually adjusts the range to maintain the best balance between accuracy and resolution.

6. Overload Protection

If the measured value is too high for any available range, the multimeter's auto-ranging feature prevents an overload condition by selecting a higher range or displaying an "overload" warning. This protects the multimeter from potential damage and ensures safe usage.

One final note: while auto-ranging is a convenient feature, there might be instances where manual range selection is preferred, especially when you need to focus on a specific range for precision or if you're working in environments with potential interference. However, for many routine measurements, auto-ranging can be a great tool that simplifies the measurement process while maintaining accuracy.

ISO/IEC 17025 Accredited Multimeter Calibration

Fox Valley Metrology proudly offers accredited precision measuring instrument calibration services of Multimeters. We calibrate all types of Multimeters at our offices throughout the country, meaning we are sure to have local Multimeter calibration services near you.

• ✓ ISO 17025 accredited calibration vendor
• ✓ Broadest calibration scope in the industry
• ✓ 3-5 day turnaround time for laboratory calibrations
• ✓ Pickup and delivery service options available
• ✓ Onsite calibrating service options

Learn More