Instruction Manual Addendum
(Advanced Models Only)
A large surface usually cannot be characterized accurately by a single measurement. Variations due to blast method and substrate preparation, in peak to valley heights, in measuring technique, etc. require an analysis of several measurements taken over a large surface area.
The PosiTector SPG makes this analysis quick and easy.
There are several ways to measure surface profile with the PosiTector SPG…
Place the probe FLAT on the surface to be measured (such that the tip of the probe reaches into the bottom of a profile valley). HOLD STEADY. The Gage will BEEP twice and display the measurement.
When selected, the PosiTector SPG continuously updates running average and standard deviation calculations. Maximum and minimum values are also tracked while measurements are being taken. The last measurement can be deleted with the (-) button, while the (+) button clears all statistics.
The PosiTector SPG can record readings in memory for printing to the optional Bluetooth wireless printer, transferring to a computer or synchronizing with PosiSoft.net. Readings are time stamped as they are stored. Groups of readings in the Advanced model are called Batches.
SmartBatch allows the user to set up measurement criteria to comply with various standards and test methods published by organizations including ASTM, SSPC, ISO, IMO, US Navy, SANS and AS.
The PosiTector SPG measures the depth of a single valley in relation to the height of the surrounding peaks using a pointed, cone-shaped probe.
A single depth measurement generally does not adequately characterize the surface profile of an abrasive blast cleaned surface. Repeated gage readings often differ due to surface irregularities even at points close together. Therefore, many organizations and contract specifications require multiple measurements be taken and analyzed to produce a final result that better characterizes the surface.
The SmartBatch menu option sets-up the PosiTector SPG to comply with various standards and test methods published by organizations including ASTM, SSPC, ISO, IMO, US Navy, SANS and AS.
When the Memory->SmartBatch menu option is selected, the following parameters are available for adjustment:
#/Spot – The number of individual gage readings required per spot surface area. A spot is typically a minimum 4cm (1.5inch) diameter circle. Also known as a sub-batch.
Lo Ignore – The number of low individual gage readings in the spot group that will be excluded from calculations. They will, however, be stored in the spot (sub-batch) and will appear in printouts and in PosiSoft.net.
Hi Ignore – The number of high individual gage readings in the spot group that will be excluded from calculations. They will, however, be stored in the spot (sub-batch) and will appear in printouts and in PosiSoft.net.
Note: The “Lo Ignore” + “Hi Ignore” total must be less than the “#/Spot” value.
Spot Min – A minimum height value used in a pass/fail test. A “fail” condition will occur if the spot average is below this value.
Spot Max – A maximum height value used in a pass/fail test. A “fail” condition will occur if the spot average is above this value.
Spot/Batch – The number of spots (sub-batches) required per measurement test area (batch).
Batch Min – A minimum height value used in a pass/fail test. A “fail” condition will occur if the batch average is below this value.
Batch Max – A maximum height value used in a pass/fail test. A “fail” condition will occur if the batch average is above this value.
Default: This setting generates results close to those obtained with replica tape and drag stylus methods.
At each location take ten readings. Discard all but the highest single value. Test 5 locations. Report the mean of the 5 maximum values.
ASTM D4417 “Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel”
At each location take ten readings and determine the mean. Repeat for all locations. Report the mean of the means.
Australian Standard AS 3894.5 “Site testing of protective coatings. Method 5: Determination of surface profile”
At each location take ten readings. Discard the 5 lowest readings and determine the mean of the remaining 5 readings. Test 5 locations. Report the average profile height measured for readings in excess of 100 microns. For profile heights below 100 microns, report the nominal profile height (fine 0-44um, medium 45-70um, coarse 70-100um, very coarse >100).
South African National Standard SANS 5572 “Preparation of steel substrates before the application of paints and related products – Surface roughness characteristics of blast-cleaned steel surfaces – Profile of blast-cleaned surfaces determined by a micrometer profile gauge”
At each location take five readings. Report each reading, the mean of the five readings at each location, the mean of all the readings, and the maximum reading.
SSPC (proposed draft standard)
Take three readings and report the mean. The mean shall not be less than the min specified and shall not be greater than the max specified.
Here is an example of how results might look using some of these test methods: