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Options for testing Relative Compression
Listed below is a handful of recent videos on the topic of Relative Compression testing. We begin our review of Relative Compression with a thorough overview from Mike at NGK Technical Testing. Additional videos show how to do RC testing using Current, Voltage, the DLC, and PicoDiagnostics.
We finish it off with Brandon Steckler who explains the advantages of using a lab scope for RC and the disadvantage of using a traditional compression gauge. He uses AC Coupling.
RC Overview
Mike Becker with NGK Technical Training explains why to do RC tests and walks you through the setup of a Pico to do RC with a high current probe.
Blue channel - Amperage
Red channel - Synch
RC via Current and Voltage
Justin at JM Diagnostics uses his Pico to do relative compression tests and compares voltage and amperage using the Pico 2000A/200A current clamp BNC.
Blue channel - Voltage
Green channel - Amperage
Red channel - Trigger and Synch
RC via Voltage
When you don't have an amp clamp, Oz Mechanics shows an alternative way to view Relative Compression test using voltage.
Blue channel - Amperage
Red channel - Voltage DC
What do you think will happen when he then switched to AC Coupling, then swaps the leads to invert the signal.
RC via DLC
Cody’s Auto Diagnostics uses the uScope to check RC via the DLC.
RC via Pico Diagnostics
Mike the Disgruntled Mechanic shows how to do very simple Relative Compression test using PicoDiagnostics.
RC via Current
Matt Fanslow shows how to customize the Pico software to use a Fluke a high current probe, setup up a trigger, zoom the waveform, use cursors. View at Diag.Net, membership required.
RC via PSI using a Transducer with Pico Diagnostics
Matt Fanslow explains how to use the Pico WPS500x Transducer with PicoDiagnostics to prefom a RC test that gives results in PSI. View at Diag.Net, membership required.
Why do RC with a Scope?
Brandon Steckler (Trained by Techs) demonstrates the differences of using a mechanical compression gauge VS a scope "to deliver a tremendous amount of information...to increase efficiency and still maintain accuracy. He uses AC Coupling which does not require a current probe.
Analyze an RC now!
1. Download and install "PicoScope 6 Automotive" software. It is free!
2. Download these two files to your desktop. They are RC captures from a Pico, one good and one bad.
- Subaru Outback 2013
- Toyota Corolla 2009
3. Open "PicoScope 6 Automotive" and go to File Open and locate one of the files.
4. Is it a good or a bad?
5. Remember to use the Zoom, the Cursors, and the Low Pass Filter.
5. Let us know if you have any questions.
