Wireless Magnetic Field Sensor For Physics

Quick Answer: The Redy wireless magnetic field sensor measures magnetic flux density, the strength of a magnetic field at its sensing tip, and sends readings wirelessly for logging. A wireless magnetic field sensor is used to measure fields around magnets, coils and solenoids and to see how they vary with distance and current.

Measuring a Field Students Usually Only Draw

Most students first meet magnetic fields as iron-filing patterns or compass needles, which show direction but not strength. School magnetic field sensors generally use a Hall-effect element: current through a thin semiconductor is pushed sideways by the field, producing a small voltage proportional to the field component that passes through the element. Readings are usually shown in millitesla or gauss.

The sensitive direction matters. Rotate the sensor and the reading changes, peaking when the field passes straight through the element. With that in mind, students can plot field strength against distance from a bar magnet, show that the field inside a solenoid grows with current and with turns per unit length, and compare it with the weaker field beyond the ends. The title does not say whether the sensor measures along the tip axis or across it, nor what its range is.

For a visual companion to the numbers, the magnetic field mapping apparatus shows field patterns, and a solenoid working model provides a coil to investigate.

Specifications

Measures	Magnetic flux density at the sensor tip
Principle	Usually a Hall-effect element in sensors of this kind
Units	Commonly millitesla or gauss
Output	Wireless logging
Range and sensing axis	Confirm at enquiry

Applications

Field strength against distance from a bar or horseshoe magnet
Field inside a solenoid as the current changes
Field around a straight current-carrying wire
Detecting the Earth’s magnetic field, if the sensor has a sensitive range

Care & Handling

Zero the sensor away from magnets and steel furniture before measuring.
Hold the sensor tip still, at a fixed orientation, for each reading.
Do not let strong magnets snap against the tip; knocks can damage it.
Store the sensor away from magnets.

Why Choose LabEquip

Physics departments teaching electromagnetism buy field sensors to put numbers on experiments that are otherwise only qualitative. LabEquip catalogues this sensor within its chemistry lab equipment; range details are available through the contact page.

Frequently Asked Questions

How does a Hall-effect sensor measure a magnetic field?

A magnetic field pushes moving charges sideways in a current-carrying semiconductor, which creates a small voltage across it. The voltage is proportional to the field passing through the element, so it can be converted into a field reading.

Why does the reading change when I rotate the sensor?

The element responds only to the part of the field passing through it. The reading is highest when the field crosses the element squarely and falls to zero when the field runs along it.

What units does a magnetic field sensor use?

Most show millitesla or gauss; one millitesla equals ten gauss. The Earth’s field is small, a fraction of a gauss, while a classroom magnet close up is many times stronger.

How do I measure the field inside a solenoid?

Insert the sensor tip along the axis of the coil, zero it with no current, then record the field as the current is increased. The field is roughly uniform in the centre and weaker near the ends.

Can it detect the Earth’s magnetic field?

Only if its range and resolution are fine enough, as the Earth’s field is weak compared with magnets. Turn the sensor slowly in a horizontal circle and look for a small, steady change in the reading.