Agilent English 2013-03-22 PDF 426 KB 5990-3218EN c20130617 [4] free download

File name English _ 2013-03-22 _ PDF 426 KB 5990-3218EN c20130617 [4].pdf

MEASUREMENT TIPS Volume 5, Number 1 Improving Digital Multimeter Throughput REDUCING TEST TIME Snapshot: Testing Automotive ECUs Whether your electronic test is in A major supplier for the automobile industry was making and testing a manufacturing, design validation, electronic control units (ECUs). During final test of the ECUs, dozens of or R&D environment, reducing your DMM voltage and resistance measurements needed to be made. The test test time translates to lower cost time per ECU was running about 43 seconds. By rearranging the tests to and shortened product develop- group all of the voltage measurements together and all of the resistance ment schedules, both of which are measurements together, the manufacturer was able to reduce test time clear benefits. The vast majority of per ECU by about 3 seconds. The manufacturer then evaluated the tem- electronic tests involve using a digital perature of the environment that housed multimeter (DMM) at one time or the test equipment and found it to be very another. There are a variety of ways stable. As a result, test engineers decided to reduce DMM measurement times to do a single zeroing measurement at the to improve overall test throughput. start of the voltage measurements and a Of course, test time improvements single zeroing measurement at the start sometimes require compromises in of the resistance measurements in other areas, but knowing the trad- order to turn off auto zero. This saved eoffs involved in throughput improve- an additional 6 seconds for a total ments and identifying what is impor- savings of 9 seconds. The test time was tant in your specific test situation will reduced from 43 seconds to 34 seconds, help you determine which tradeoffs a 21% reduction that increased throughput make the most sense. by more than 25%! Auto zero: Reduce the number of changes Auto range variations Accuracy versus test time Changing functions or measurement Auto range time can sometimes Auto zero is a DMM feature that ranges also requires extra time contribute to longer test times, but helps you improve accuracy. When in most DMMs. Try to group your not always. The time to auto range you use the auto zero feature, the measurements to minimize function varies with the DMM design. DMMs DMM makes an additional zeroing changes and range changes