Here are the Amazon Reviews of the Bartol Mag-Probe posted on the Internet.
These Amazon Reviews will give you a much better understanding of how popular the Bartol Mag-Probe is when separating Electrical problems from mechanical problems on solenoid valves and relays
Most Helpful Customer Reviews
By Carol-Ann Wilkinson on November 3, 2009
I’m an electrical field service tech working with stuff like ac/dc (up to 100Vdc and 220Vac) “icecube” relays, contactors and solenoids.
I found these years ago (amazed that they are available on Amazon). They are indispensable and one of the best tools I have when fault finding.
No Batteries required. Works on ac or dc coils as it senses the magnetic field.
Small and lightweight, you can tape them to whatever it is you want to monitor, whether it’s on a circuit board or, say, a solenoid inside a machine that’s not accessible when the machine is running.
A bright red LED is in the top and activates when it senses the field, making it really easy to see.They come in the H or HS versions. The HS (High Sensitivity)is the one to get as it works in virtually every situation. Both come with a magnetic rubber “donut” ring that can be slid onto the tapered tip to increase the sensitivity even further but I haven’t found it necessary with the HS version.Couple of things to look out for –
1] They are somewhat delicate. Dropping them can sometimes cause them to quit working. Although, sounds stupid, you can often bring them back to life by deliberately dropping them again!
2] Over time the LED gets dimmer to a point where they are unusable but that depends on how often you use them and for how long they are activated. If you use them a few times a week they could last for years (as long as you don’t drop them in the meantime <grin>.)
3] Because of point 2] make sure you don’t store them near anything magnetic. They come with a shield that slips over the tip to protect them from this but best to be safe than sorry.
Note that the magnetic “donut” clips into one of the end caps of the plastic tube that it is shipped in and will activate it if the shield is not in place.
Also, this tube is very flimsy and crushes very easily.Good set of instructions supplied.
Under normal use the Mag-Probe works flawlessly. It is accurate, quick to separate a mechanical from electrical problem with a solenoid valve or relay. It can work in every environment, from 80 degrees below zero Fahrenheit, up to +160 degrees Fahrenheit. It is intrinsically safe to use in explosive environments, and can be used 40 feet below the surface of water and in a vacuum. It will test some of the smallest to the largest relays on the market today. Ultimately it is the tool to start with when separating mechanical from electrical problems on solenoid valves or relays.