The Problem

Emglo, a division of Black and Decker, needed a Quality Control (QC) testing system for their new line of portable air compressors. The QC system needed to perform a complete operational test of each air compressor produced at the plant. The test data had to be archived and the test station operator had to be alerted to the results of each test. One test needed to be completed every two minutes in order to keep pace with production capacity.

The Solution

REAL Controls designed and fabricated three QC testing stations for Emglo. Each station collects data consisting of electrical current draw, line voltage, power consumption, power factor, pump pressure and pump-up-time for each compressor. This data is stored in a SQL database for each compressor tested.

The QC operator interacts with a touch-screen PC, such as the one shown above, to set-up the test procedures, perform the QC tests and view the results. A barcode system is used to facilitate correlating the results of each test with the correct compressor. A step-by-step test procedure within the PC program minimizes the likelihood that an operator will make a mistake in conducting the QC tests. Alarm functions built into the software alert the operator when a compressor fails a test and indicates the reason for the failure. A failure log is then printed and sent, with the compressor, to the rework area. Statistical Process Control (SPC) analyses are conducted on the test results and the SPC results can be viewed on the systems operator interface PC.

The software for the QC testing station was developed using National Instruments LabVIEW product. Data is acquired via a plug-in data acquisition card and through a serial interface to an Ohio Semitronics power monitor.

The Result

The new QC system exceeded Emglo’s expectations. The simplicity of operation of the system allows little room for operator error in conducting the tests. The production and engineering departments both have easy access to the test results from the SQL database. SPC control charts, viewed on the touch screen PC, provide instant feedback to show the operator whether the manufacturing process is operating within acceptable control limits.