Tracking Force Gauges

I bought the $95 gauge and I'm extremely happy with it. Very repeatable and reliable. Highly recommended.

I read Thom's remarks in the attached thread. It helped a lot in understanding the importance ans ways of measuring VTF. It was the basis of some of my questions.

Sirspeedy,

Have you or anyone you know verified the accuracy of this gauge with a calibrated weight?

Thanks.

andrew

Drubin,

That's correct. The gauge specifies an accuracy of +/- 0.002g. I would be happy with an order of magnitude worse. All else aside, I feel a lot more comfortable buying a gauge where measurments are perfromed in the middle of the range as opposed to at the bottom end. It also seems that it's easier to position the stylus tip on the center of the measuring platform.

I think I'll give it a try.

ALL,

Key question. Does the $95 gauge have a magnetic surface that the stylus would be positioned on? Will the magnet in a cartridge affect the accuracy of the reading with this gauge?

Vetterone,

Thanks for that input. I was planning to purchase a calibrated weight and checking it for accuracy AND repeatability. It is good to know you are getting good results on both.

Andrew

Vetterone,

I wonder if they are using a 310 or 316 grade of SS. Below is some background of magnetic properties of stainless steels. I have one on order and will check this with a magnet.

Background

Magnetic permeability is the ability of a material to carry magnetism, indicated by the degree to which it is attracted to a magnet. All stainless steels, with the exception of the austenitic group, are strongly attracted to a magnet.

Austenitic Grades

All austenitic grades (300 series) have very low magnetic permeabilities and hence show almost no response to a magnet when in the annealed condition; the situation is, however, far less clear when these steels have been cold worked by wire drawing, rolling or even centreless grinding, shot blasting or heavy polishing. After substantial cold working Grade 304 may exhibit quite strong response to a magnet, whereas Grades 310 and 316 will in most instances still be almost totally non-responsive.

The change in magnetic response is due to atomic lattice straining and formation of martensite. In general, the higher the nickel to chromium ratio the more stable is the austenitic structure and the less magnetic response that will be induced by cold work. Magnetic response can therefore be used as a method for sorting grades of stainless steel, but considerable caution needs to be exercised.

Andrew

Guys,

Thanks. I ordered one a couple of weeks ago but haven't received it yet. I'm glad that everyone is happy with it. I like the fact that its range is only 5g, its accurate, and non magnetic.

QUESTION:

Many have said that it's important to measure the VTF at record level. Instead of making platfroms and jigs, etc, what about increasing the VTA by roughly the height of the scale. I guess this should only be done if you have a ultra-reproducible VTA adjustments.

PS, Dan I'm looking forward to your Denver trip report.

Andrew

Guys,

One more thing to add about the 95 gauge. I've noticed that as the cartridge is lowered down onto the gauge, and just before touchdown, the gauge begins to read negative. In my case it can be as mach as -0.03 g. Although the gauge is advertised as being non-magnetic, I suspect that there is some magnetic attraction between the cartridge magnet that slight pulls the gauge in its direction. The actual negative component is probably greater when the needle is on the surface. Therefore, the actual VTF is probably higher than indicated, albeit repeatable.

Have you experinced this?

Vincentkkho,

The more I thought about this the more I think I need to retract my assertion on a false reading as a result of the magnetic attraction. Certainly with the cartridge suspended over the gauge, one sees a negative reading appear. However, when the stylus touches down and makes contact and the arm is free to move, I think there is no upward force and the gauge is truly reading the VTF. What do others think?

Andrew