Checkline PT-RTR - Manual (Page 8)

5
How to Measure How to Measure
Prepare the test surface
Burnish the replica tape (create a replica)
1. Prepare the test surface
2. Burnish the replica tape
3. Prepare the Gage
4. Measure
Locate a representative site for measurement.
Clean the surface to be tested. DeFelsko
recommends the use of the included putty to
remove dust, debris, or residual blast media from
the surface. Firmly press the putty onto the surface
using your fingers, and remove.
Press-O-Film Replica Tape Press-O-Film Replica Tape
Press-O-Film provides a simple way to obtain an impression of a
surface for analysis. It consists of a layer of crushable plastic micro
foam affixed to a 50.8 µm (2 mil)
incompressible polyester film. When
compressed against a roughened surface, the
foam collapses and acquires an accurate
impression, or reverse replica, of the surface. It is available in a
number of grades to accommodate measurements in different
profile ranges.
Placing the compressed tape (replica) into the PosiTector RTR
gives a measure of the average maximum peak-to-valley height of
the surface roughness profile. The Gage automatically subtracts
the thickness of the polyester substrate from all measurements.
Select the appropriate grade of replica tape based on the target
profile. See tape instructions for assistance.
Pull a single adhesive-backed replica tape free of its release paper.
A “bull’s eye” circle of paper should remain on the release paper
(it is not used for measurement).