Shars - Herramienta desmagnetizadora de placas, 120 V 202-1170 R

Like many, I bought one of the little weenie demagnetizers, and while it sort of works, it doesn't suit many objects simply because it's so small. This unit can demagnetize nearly anything you'd ever need done. I do metalwork as a hobby and over time, all my tools end up magnetized. Drove me nuts how metal chips and grit ended up coating them - but no longer!

This product worked exactly as advertised. It took less than 20 seconds to accomplish my initial task!I inadvertently placed a work light with a magnetic base on top of two 3” rubber air intake hoses while working on my sailboat engine. Turns out the hoses have metal wire loops inside to keep them from collapsing. Unbeknown to me, these metal rings became magnetized and affected my autopilot compass mounted nearby. The compass readings went all crazy and rendered the autopilot unusable. I temporarily removed the compass from the area affected, then I suspended this demagnetizer from two rope handles and passed it along the length of both air intake hoses. Tada! Problem solved. Autopilot recalibrated and now working perfectly. Saved me hours of time if I would have had to source replacement air intake hoses and install them in extremely tight spaces.I then put this tool to work demagnetizing all my screwdrivers, driver bits, needle nose pliers, scissors & Allen keys. Just a few seconds each was all that was needed. (Using magnetized tools and work lights on a sailboat are not a good idea. Steering compass and autopilot compass are very sensitive.) I am very pleased with the performance of this device. Highly recommended for any demagnetizing projects.

No problems

Cumple al 100 por ciento su función

So far, this has been working great. The instructions were garbage, and I can't seem to find any solid source of info online on using a demagnetizer like this. But it seems to work if you pull the material across the plate slowly horizontally. Some demagnetizers work by pulling the material away vertically from the plate. I dunno. Do make sure you've got a good hand on your material though, because the magnets inside this demagnetizer do take it for a ride! I laid down a layer of tape on the metal surface so as not to scratch the material/work piece.

BACKGROUNDDegaussing (demagnetizing) is a bit of a lost art seldom practiced nowadays. Magnetic media (audio and video tapes) are near-nonexistent, and even avionics repair shops at airports typically no longer possess degaussers as there is no modern need to reduce the effects of extraneous magnetic fields on airplane compasses from welded tube-frame construction.I needed to degauss metal structures in the dash of my Miata because I was installing a magnetic compass in the dash (I can get turned around on country roads when it’s overcast), so I felt fortunate that Shars offers this size of degausser (vs. the silly little tools barely suitable for degaussing screwdrivers and cassette tapes).EVALUATIONWhat you need to generate magnetic fields is “amp turns” in a magnetic solenoid, not “watts.” As I was deeply skeptical of their seemingly absurd claim of “600 watts,” the first thing I did upon receiving the Shars 202-1170 was check its power consumption; it is actually only 68 watts (see photo), which is GOOD; I’ll explain: They call it “600 watts” because it draws 4.35 amps (4.35 A × 120 V = 522 watts). However, magnetic coils and solenoids have their voltage and current highly out of phase (their “power factor” is very low, ~0.13 instead of 1.0 seen with purely resistive loads like tungsten-filament lightbulbs). So, when you account for the low power factor, the degausser’s wattage is equally low, which is ACTUALLY WHAT YOU WANT lest you melt down your degausser after only 90 seconds. They should just advertise “amp-turns” and peak magnetic field intensity, in teslas. Claiming wattage for a degausser is nonsense, and stating that 522 watts is “600 watts” is exageration to boot.I deducted one full star due to this wild “600 watt” claim, which is like claiming a “two-million lumen flashlight,” which makes it difficult for potential buyers to do comparison shopping.The second thing I did was cut off the mounting ears so the 202-1170 could squeeze into the dash of my Miata (see photos). I also covered the pretty stainless platen with cardboard to protect it and reduce vibrational chatter (larger metal objects will violently vibrate when they are close to it).PERFORMANCEAfter dozens of experiments where I used an iPhone app to measure DC magnetic fields (in microteslas, or µT), I found a trivially easy technique to use the 202-1170 to completely degauss everything from small screwdrivers to heavy and large mounting brackets to which automotive dash components are mounted. The 4.35 amps times whatever number of turns the solenoid inside the 202-1170 has is more than enough to do the job.HINTThe classic technique for degaussing ferromagnetic items is to hold them very close to the platen on the degausser, turn it on, and slowly move the item away in an ascending and enlarging helix. But this technique is an artform requiring practice because one must CAREFULLY back away from the degausser (or move the degausser away from a larger immovable object) in a manner that ensures there is an inexorable decay in the magnetic field with ABSOLUTELY ZERO brief increases in field strength. It’s harder to do than you might think.As you can see in the photo of the Miata dash, there was no room to back the 202-1170 away from the structures being degaussed, so I had to come up with an alternative method of reducing the magnetic field. I found that by powering the 202-1170 with a variac (an adjustable AC voltage source), I could simply turn on the variac at full power and slowly twist the dial setting to zero over about 20–30 seconds. Probing with the iPhone’s app measuring microteslas, I found it was crazy easy to repeatedly reduce magnetization to absolutely nothing… without failure.Once I was back in my workshop, I tried the technique on many other items (see photo with the screwdriver atop the 202-1170) using the variac and obtained the same excellent results, which were superior to the “helical movement” technique.