What is Mag-Probe?

This magnetic sensing probe is an intrinsically safe, non-contact instrument, which allows troubleshooting without schematics or special training while eliminating time consuming and cumbersome hook-ups.

  • No calibration required
  • Works effectively from -80 to +160°F
  • Requires no direct electrical connection
  • Suitable for high risk explosive environments
  • Waterproof, not affected by corrosion or salt spray
  • Ability to check solenoid valves and relays while equipment is operating
  • Isolates problems as electrical or mechanical in seconds, without a schematic
  • Detects transient pulses and momentary loss of power as low as 10 milliseconds
  • Detects residual magnetism – Great for checking relays before installing on aircraft
  • Long life power source and low current LED lasts for at least 5000, 5-second operations
  • Variable Sensitivity – detect 1 gauss using ring magnet – 3 gauss without using ring magnet
  • Reduce Sensitivity by sliding on the white protective shield – Reduce detection of overlapping magnetic fields
  • Magnetic sensing instrument used to troubleshoot AC and DC powered solenoids, solenoid valves, relays and heat controllers

3-1/2″ long. Wt: 1 oz. (USA) High Sensitivity Model, for all Electrical Solenoids, Relays, Coils and Reed Relays

The Mag-Probe® will allow many of its users to get their money back on the first test.

Mag-Probe Interactive Downtime Spreadsheet

Mag-Probe Interactive Downtime Spreadsheet

Compute Your Lost Potential Revenue Instantly

The profits generated by reduced troubleshooting time make the Mag-Probe the obvious choice for a CEO, President or Owner, of any service or manufacturing company. Why? Because typically the return on your Mag-Probe investment will be one test.

Mag-Probe Maintenance & Production Line Applications by Industry


Mag-Probe® magnetic field detector is a great tool for testing operation and troubleshooting of many aircrafts systems. Mag-Probe® can be used for testing of aircraft relays, fuel valves, bleed valves and much more.

Oil and Gas

The Mag-Probe® will always protect oil and gas electrical technicians in explosive environments. It is completely encapsulated in a non-conductive material and no contact has to be made during testing.

Elevators | HVAC

Elevator technicians worldwide are reducing troubleshooting considerably using the Mag-Probe®. Where time is money, reduced down-time is important.

Nuclear & Coal Fire Power Plants

The Mag-Probe is being used on Nuclear Power Plant Solenoid Valves because it is intrinsically safe to use in explosive environments . . .

Railroad Locomotives

I’ve been using the Mag-Probes for 10 years as a locomotive electrician and it is one of the tools I use on a daily basis . . .

Semi-Conductor | Bottling | Food Processing

A Mag-Probe can be used in the manufacturing of spare parts which supports production line maintenance . . .

Automobiles & Diesel Trucks

The ignition coil test will separate electrical from mechanical problems in seconds.  

“I cannot believe how fast this product finds the problem valves and relays on cars . . .

Heavy Equipment | Mining

It is a definite must tool to have!  I use it for trouble shooting aerial man lifts,  (Booms and Scissors) forklifts, any machine that is run by Electric over Hydraulic operation . . .

Irrigation & Water Treatment Plants

With all the bugs, rodents and lizards and bottles that live in the valve boxes it makes  it difficult conducting a test because many of the valves es boxes  are in the earth . . .

Programmable Logic Controllers

 “One of the most innovative and inexpensive tools of this century that offers an astronomical ROI” Don Fitchett

A non-contact instrument for testing the operation of AC or DC relays and solenoids. Sensitive enough detect the magnetic field generated by tiny “ice cube” relays. The Mag-Probe can also make tests through most shielded solenoid valves and relays and is completely self-contained and sealed so it can be used in explosive environments.

Additional Mag-Probe Applications

Military Defense, Space Applications, Cargo Shipping, Medical Devices and Laboratory Research

Effective Tool when trouble shooting electrical systems with solenoid valves, relays or coils. The Mag-Probe can be used in any environment including Clean Rooms, Explosive environments, Underwater, Temperatures Ranging from -80°F to 180° F, and in a Vacuum. It can also be used on the some of the smallest relays in the world down to 1 gauss and the largest solenoid valves using the de-sensitizing shield to block over lapping fields. It has a shelf life of 10 years and will identify North and South Poles on any magnet. It also comes with a test magnet to make sure the tester is working correctly. There are unlimited applications for the Mag-Probe. When the light comes on you know you have the presence of current, continuity, and voltage in one quick test and will work while equipment is operational, safety permitting. Great for quickly determining which direction to go in when you are trouble shooting electrical coils, solenoid valves, relays and/or anything that has an electrically energized coil or winding.

Mag-Probe Manufacturer
HSI Sensing - Their Story

David Posey, Travis Posey, Ryan Posey

William Posey wasn’t just an entrepreneur. He was an engineer. And he didn’t just start a company. He pioneered a technology…one that over the years has made a lot more technology possible, in everything from pacemakers to pilot ejection seats and security systems to space stations.

Testimonial & Reviews

You’re Mag-Probe is great, I wish I had thought of it. The company I work for has over 150 electronic techs on staff and all of us have Mag-Probes provided by the company . . . Mark Lindsey, Electrician

Residual Magnetism Test

(208) 631-3330

Bob Bartol - CEO
Inventor of the
Bartol Mag-Probe

Has spent a lifetime lowering downtime in industry. He has created amazing solutions to kill cancer, solve the mussels problem in our water systems,and the over bearing rat situation overtaking our cities using non-toxic methods and procedures. Read about his ideas and solutions.