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We Do Calibration Better With GageMaker Mic Trac 4000

Posted by Barry Ward ,Aug 3rd 2016

Precise Calibration Services at TestEquipmentUSA

We have upgraded our equipment to do even more precise calibrations that enable you to measure with confidence. One of those tools a Gage Maker MicTrac 4000.

This is a device that allows us to do a dimensional calibration with an accuracy of 10µin. This is 0.000010” resolution! At this level, even putting your hand on the unit could add enough heat to expand parts of it more than this amount.

How We Get Precise Measurements

It amazes me that cal labs can do things this accurately and yet NIST works at much higher accuracies than this. How do they do this? First, to be accurate, you need to keep your temperature very constant and close to 68°F (20°C). Most labs, like ours, can deliver precise calibration services while keeping the temperature at 68 ± 2, but NIST probably keeps theirs at 68±0.2. This constant temperature reduces the size variation of all materials. Steels expand at the rate of between 5 and 10 µinches/inch/degree F, depending upon the alloy.

This means that a device that is 12 inches long will expand by about 0.0012 in at 78°F [10 µinches/inch/degree F * 12 inches * 10°F]. While this may not seem like a lot, this is over 1 thousandth of an inch. Most calipers and micrometers can easily measure this variation. Machinists today, especially those using CNC machines, can easily hold a tolerance of ±0.001 inch; CNC machines can usually hold tolerances of ±0.0001 inch. The second thing that NIST probably does is to use lasers to make measurements. A laser has an advantage over any “physical” system in that it is not much affected by changes in temperature, an important advantage for delivering precise calibration services.

Measurements With Lasers

A laser’s “frequency”, or light color, does not change much due to temperature; nor does its speed change much – it is always the speed of light (about 186,000 miles/second). Measuring tools that use lasers send a pulse of light and start a clock at the same moment, then stop the clock when they get a reflection. Divide this time in half (because it is going there and back, or twice the actual distance), and multiply by the speed of light, and you know how far away the reflector was.

Today’s technology allows accurate timing down to femtoseconds (10-15 seconds). This gives a resolution of about 12µinches. If you and I can afford to buy equipment accurate to the level imagine what a national laboratory can afford!

Call for Precise Calibration Services at TestEquipmentUSA

So what can we do with our new toy? Many things. We can calibrate calipers up to 36” long. We can do micrometers (ID, OD, Depth) to this same limit. We will be able to measure most threads to verify Pitch Diameter and Major Diameter. We will be able to check pitch for threads. There are very few common dimensional devices that we will not be able to calibrate.

To see the benefits of our MicTrac 4000 in action for your equipment, contact our team of experts today. We have everything you need to measure with confidence on your next project.