Measuring inner and outer diameters of plug gages requires meeting a certain level of accuracy, and BorgWarner Morse TEC (Ithaca, NY), a manufacturer of automotive timing components, felt it wasn't consistently meeting those levels using a micrometer. Three years ago, the company decided to do something about it.

Using the Helio-Com by Atlantic Metrology (New York), technicians are able to measure plug gages within 0.1 micron repeatedly. "It was the level of accuracy we have never attained before," said Joe Rypl, metrology lab supervisor for BorgWarner. "We didn't have anything that would measure that accurately."

BorgWarner chose the Helio-Com because of the temperature sensors that gage the temperature of the part being measured. Temperature is critical to measurement accuracy. If the thermal expansion is greater than the tolerance allowed for the gage, the measurement data will be incorrect and the size of the gage is unknown. According to Rypl, the standard wait time to measure a gage in a temperature-controlled room is 4 hours, but now a technician can measure the gage immediately.

The gage uses Direct Data Link (DDL), a feature that interfaces with gage calibration software. Technicians measure the part on the tool and then hit an enter key. The program keeps track of all measurements and calibration due dates for QS-9000 requirements.

According to Rypl, his lab inventories thousands of plug gages. For every plug gage, a certificate had to be purchased. "These certificates cost about $40 each -- sometimes they cost more than the plug gage," said Rypl. With the new gage, the size of gages is verified without the use of a third-party certification.

The biggest challenge was achieving the cleanliness required for accuracy and repeatability. Special cloths and paper are used to clean the machine and gages before all measurements. Any lint on a gage could create an erroneous measurement.

"The equipment has been very reliable and we haven't had any problems," said Rypl.-- Kimberly Schmidt

BENEFITS

• Repeatable accuracy within 0.1 micron.
  
• A temperature probe lets technicians measure gages immediately.
  
• Savings of $40 per gage because a certificate is no longer needed to verify that a gage is compliant.