How to Test a Hall Effect Sensor with a Multimeter

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How to test a Hall effect sensor with a multimeter comes down to two bench checks: the DC voltage at the sensor’s supply pin, and the output voltage with and without a magnet. The sources we opened give supply and output values only for named devices, so the figures that count are the ones in your own sensor’s datasheet. This guide covers a small DC sensor on the bench, out of any vehicle or controller.

Electrical safety

Work on mains circuits can kill. Before you measure anything, check that the meter’s CAT rating suits the circuit you are testing, and read the rating from the listing or the manufacturer’s manual. Panel and service work belongs to a licensed electrician.

OSHA’s electrical incidents eTool says fatal electrocution is the main risk for construction workers, and Fluke’s safety page refers to deadly industrial electrical shock hazards. OSHA’s energized-work rule limits work on circuit parts that have not been de-energized to qualified persons. That rule does not use the word licensed, so the licensed-electrician line is a site rule, not a quoted requirement.

A CAT rating sets the installation category a meter is built for, and Fluke’s glossary says the higher the rating, the more demanding the testing criteria. Klein’s MM300 manual lists CAT III 600V and says to use only CAT III or CAT IV rated test leads, and its MM325 manual gives the same rating. Read your own meter’s rating from its listing or manual. For how voltage testers differ from multimeters, see our explainer on how voltage testers work.

This guide stays with low-voltage bench work: a DC sensor powered from a source inside its datasheet range. It gives no steps for live mains, panels, outlets or service wiring. If a sensor installation would need that work, stop and bring in a licensed electrician.

Quick answer

• Read the datasheet first. It names the pins, the supply range, the output type, whether a pull-up resistor is needed, and the magnet pole that switches a digital output.
• Set the meter to DC volts and measure the supply pin against ground. Stop if that reading is outside the datasheet’s supply range.
• Measure the output against ground with no magnet, then with a south pole at the branded face.
• Compare each reading with the datasheet, because digital and analog outputs look different.

What you need before you start

Allegro’s unipolar note defines the Hall effect as the measurable voltage present when an applied current is influenced by a perpendicular magnetic field. You do not need the physics for the bench check, but three terms come up in datasheets and in this guide.

• Branded face: the package face marked with the part number. Allegro’s applications guide says the active area sits closer to that face, so the magnet goes there.
• Pull-up resistor: a resistor between the supply and an open output pin. Allegro says common values range from 1 to 10 kΩ.
• Gauss and millitesla: Allegro gives 1 G = 0.1 mT, and the TI datasheet uses millitesla, so convert before you compare.

You need a DMM with a DC volts function, a DC source inside the sensor’s supply range, and a magnet. The sources give no magnet strength for a generic sensor, so judge the magnet against the operate point in your datasheet. A current-limited bench supply is our own assumption, not a sourced rule.

For a broader look at meter choice, read our multimeter roundup. If you are picking a meter mainly for DC voltage, the DC volt meter roundup is the closer match.

Step 1: Identify the pins and the output type

Match the pin labels in the datasheet to the package on your bench. The TI DRV5053 datasheet, for example, shows a three-pin package with VCC, OUT and GND. Your part may differ, so use its own pinout.

Next, identify the output type. Allegro’s unipolar note says there are four general categories of Hall-effect devices with a digital output: unipolar switches, bipolar switches, omnipolar switches and latches. A linear sensor is different, because its output is a voltage that changes with the field.

Step 2: Set the meter to DC volts

Fluke’s DC voltage procedure starts at the dial. Turn it to DC voltage, marked with the DC symbol. Fluke advises that if you are unsure between DC voltage and DC millivolts, start with DC voltage, which handles higher voltage.

Put the black probe in the COM jack and the red probe in the V jack. Fluke’s warning is specific: putting the probes in an A or mA input and then measuring voltage creates a short in the measurement circuit.

Fluke says it is not critical for the red lead to touch the positive point on a modern meter, because a negative sign appears when the leads are reversed. On an analog meter, reversed leads can damage the meter, so the red lead must go on the positive point there.

Step 3: Measure the supply pin

Connect the black lead to GND and the red lead to VCC, then read the DC voltage. Compare it with the supply range in the datasheet before you go further. The DRV5053 datasheet says the device is active only when VCC is between 2.5 V and 38 V, and that it will not operate when approximately -22 V to 2.4 V is applied to VCC.

Fluke’s DC guidance applies here too: even small variations may indicate trouble in a DC circuit, and the acceptable variation depends on the application. If the supply reading does not match the datasheet range, check the supply before you read the output.

The DRV5053 datasheet allows up to 40 V for transient durations only. That is a survival figure, not an operating point.

Step 4: Wait for the power-on time

Do not read the output the moment power comes on. The DRV5053 datasheet says ton must elapse before OUT is valid. Allegro’s unipolar note gives a power-on time below 1 µs for a design without chopper stabilization and below 25 µs with it. Read the figure for your own part from its datasheet.

Allegro’s applications guide also describes a settling step for its calibrated linear sensors: connect VCC, GND and VOUT to a high-impedance voltmeter, power the device, and allow one minute to stabilize. That step applies to calibrated parts only.

Step 5: Measure the output with no magnet

Connect the black lead to GND and the red lead to OUT. Keep the magnet well away from the sensor, then read the voltage. What you should see depends on the output type.

• Digital switch with a pull-up: Allegro’s applications guide says that with no applied field a digital switch is off, and its output then equals the supply voltage through the external pull-up resistor. The guide’s example uses a 12 V supply, so a reading close to the supply matches that off state.
• Digital switch with no pull-up: Allegro’s unipolar note says a pull-up must be connected between the supply and the output. Without one, a reading does not show the off state the datasheet describes. This is our reading of the note, not a figure from it.
• Analog sensor with a fixed zero-field value: the DRV5053 datasheet says the absence of a magnetic field results in OUT = 1 V.
• Ratiometric analog sensor: Allegro’s linear note says most linear Hall-effect devices are ratiometric, with a quiescent output that is typically half the supply voltage. Its A3515 example gives 2.5 V at 5.0 V with no field.

Compare the reading with the value your datasheet states. Do not assume half the supply for every analog sensor, because the DRV5053 uses a fixed 1 V output at zero field.

Step 6: Apply the magnet and read again

Bring the magnet toward the branded face, south pole first. Allegro’s unipolar note says a unipolar switch turns on in a south field and that a north field has no effect on it. Its FAQ says the magnet’s south pole is directed toward the branded face of the package.

Read the output as the magnet moves closer. The expected change depends on the device type.

• Unipolar switch: when it turns on, the output can go to logic high or logic low, depending on the output stage. The switch stays on while the field remains more positive than the release point. Read the datasheet to learn which logic level means on.
• Latch: Allegro’s latch note says latches require both positive and negative fields to operate. A south field switches a latch on, and it stays on after the magnet is removed, until a north field of enough strength switches it off.
• Linear sensor, DRV5053 example: the datasheet says a south pole near the marked side of the package is a positive field. For the RA variant, a south pole drops the output below 1 V and a north pole raises it above 1 V. The EA variant reverses that direction.

Our own assumption: hold the magnet at the same distance for each reading, so the readings can be compared. Allegro’s applications guide shows the output switching when the field reaches the operate point. Your datasheet gives the operate point for your part.

Step 7: Compare the readings with the datasheet

The table below lists what the sources we opened say for each output type. Where a source does not give a value for a row, the table says so.

Output type	No magnet	Magnet present	Source
Unipolar digital switch	Off. Output equals the supply through the pull-up in the Allegro example	On with a south pole at the branded face. Logic level for on: not stated for a generic device	Allegro unipolar note; Allegro applications guide
Latching digital switch	Keeps its last state	South field switches on; north field switches off	Allegro latch note
Analog, DRV5053 example	OUT = 1 V	RA variant: south pole drops OUT below 1 V. EA variant: it rises above 1 V	TI DRV5053 datasheet
Ratiometric analog, A3515 example	Typically half the supply: 2.5 V at 5.0 V	Changes with the field. Sensitivity 5 mV/gauss for the A3515 in this note	Allegro AN27702

Reading the results

Only the datasheet can say whether a value is normal for your part. The sources we opened give expected values for named devices, and no pass or fail limits for a generic sensor.

• A digital output with a pull-up that reads close to the supply, with no magnet, matches the off state in Allegro’s example.
• A digital output that reads low with the south pole at the branded face has switched on, but only if your datasheet says the on state is low.
• An analog output with no magnet should match the zero-field value in your datasheet. For the DRV5053 that value is 1 V.
• If the output does not change as the magnet approaches, check the magnet’s pole, the branded face orientation, and the supply reading from step 3. The sources give no fault table, so treat this as a checklist, not a diagnosis.

Common mistakes

• Probes in the current jacks: Fluke warns that measuring voltage with the red probe in an A or mA input creates a short.
• Reading too early: the DRV5053 datasheet says OUT is not valid until ton has elapsed.
• No pull-up on an open output: Allegro says a pull-up resistor must be connected between the supply and the output.
• Assuming half supply: Allegro describes the ratiometric quiescent value as typically half the supply. The DRV5053 example is a fixed 1 V.
• Wrong magnet pole or face: a north field has no effect on a unipolar switch, and the magnet must face the branded side.
• Supply outside the range: the DRV5053 datasheet limits normal operation to its stated supply range, so readings taken outside it do not show normal output.

FAQ

Can a multimeter alone show whether a Hall sensor works?

The meter can show the supply voltage and the output level, both at rest and with a magnet. The sources we opened give no full pass or fail procedure for a generic sensor, so compare with your part’s datasheet.

Why does my digital output read close to the supply with no magnet?

That matches the off state in Allegro’s applications guide example, where an external pull-up resistor holds the output at the supply voltage. Confirm that your circuit has the pull-up before you read more into the value.

Why does a DRV5053-type sensor read 1 V with no magnet?

The DRV5053 datasheet gives OUT = 1 V for zero field. Another analog sensor can use a different zero-field value, so use the figure from its own datasheet.

Does a north pole switch a unipolar sensor on?

No. Allegro’s unipolar note says a north field has no effect on a unipolar switch, so the south pole at the branded face is the field that turns it on.

What does a latch do after the magnet is removed?

It keeps its state. Allegro’s latch note says the device stays on after the magnet is removed, and it switches off only when a north field of sufficient strength is applied.

Is 12 V safe for every Hall sensor?

No source we opened says so. The Allegro applications guide uses 12 V in its example, and the DRV5053 datasheet gives 2.5 V to 38 V for that part.

How we chose

Every source is a manufacturer document or a government safety page: Allegro MicroSystems and Texas Instruments for sensor behavior, Fluke and Klein for meter steps and CAT ratings, and OSHA for the safety statements. We opened each one with curl on 2026-10-22, read the page text, and checked each quoted phrase against it. We did not use search snippets as evidence, retailer listings, or general reference sites for any procedure or safety claim. Two pages failed to load and are not cited.

What we could not verify

The sources we opened do not cover the points below, so this guide does not claim them.

• A supply range or output value for a generic small DC Hall sensor. The values we have are for named devices only.
• Pass or fail limits, or tolerances, for any sensor.
• A fixed sensitivity for the DRV5053. Its overview text gives 40 mV/mT for the RA and EA variants, while the electrical characteristics table labels the same variants 45 mV/mT. This guide gives neither figure as a target.
• The input impedance of a multimeter. Allegro asks for a high-impedance voltmeter but gives no value.
• A single complete procedure for testing a Hall sensor with a multimeter. The steps here combine Fluke’s DC voltage procedure with the behavior in the datasheets and application notes above.
• Licensing requirements. The OSHA text we opened uses the term qualified persons and does not describe licensing.
• The output polarity of your part. The unipolar note says the on level depends on design, so your datasheet decides.

Sources

• Allegro MicroSystems, Unipolar Hall-Effect Sensor IC Basics: https://www.allegromicro.com/en/insights-and-innovations/technical-documents/hall-effect-sensor-ic-publications/unipolar-hall-effect-sensor-ic-basics (opened 2026-10-22)
• Allegro MicroSystems, Latching Switch Hall-Effect IC Basics: https://www.allegromicro.com/en/insights-and-innovations/technical-documents/hall-effect-sensor-ic-publications/latching-switch-hall-effect-ic-basics (opened 2026-10-22)
• Allegro MicroSystems, Hall-Effect IC Applications Guide: https://www.allegromicro.com/en/insights-and-innovations/technical-documents/hall-effect-sensor-ic-publications/hall-effect-ic-applications-guide (opened 2026-10-22)
• Allegro MicroSystems, AN27702 Linear Hall-Effect Sensor ICs: https://www.allegromicro.com/-/media/files/application-notes/an27702-linear-hall-effect-sensor-ics.pdf (opened 2026-10-22)
• Texas Instruments, DRV5053 Hall-effect sensor datasheet: https://www.ti.com/lit/ds/symlink/drv5053.pdf (opened 2026-10-22)
• Fluke, How to Measure DC Voltage with a Digital Multimeter: https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-measure-dc-voltage-with-a-digital-multimeter (opened 2026-10-22)
• Fluke, Multimeter Common Terminology: https://www.fluke.com/en-us/learn/blog/electrical/multimeter-common-terminology (opened 2026-10-22)
• Fluke, Safety: https://www.fluke.com/en-us/learn/blog/safety (opened 2026-10-22)
• Klein Tools, MM300 instruction manual: https://data.kleintools.com/sites/all/product_assets/documents/instructions/klein/MM300_1390109ART_WEB.pdf (opened 2026-10-22)
• Klein Tools, MM325 instruction manual: https://data.kleintools.com/sites/all/product_assets/documents/instructions/klein/MM325%20Instructions_web.pdf (opened 2026-10-22)
• OSHA, 29 CFR 1910.333 Selection and use of work practices: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.333 (opened 2026-10-22)
• OSHA, Electrical incidents eTool for construction: https://www.osha.gov/etools/construction/electrical-incidents (opened 2026-10-22)