When attached to either a PosiTector Standard or Advanced body, the PosiTector
6000
FNDS
probe measures the individual thicknesses of both the paint and the zinc layers
in a duplex coating system with a single reading.
Duplex coating systems use a combination of two corrosion protection systems –
typically paint or powder coating over galvanized steel (hot-dip, electro or zinc spray
metallizing). The resultant corrosion protection is superior to either protection system
used independently.
Duplex Mode
In Duplex mode, the Gage utilizes both magnetic (ferrous) and eddy current (nonferrous) principles simultaneously to calculate and display the individual paint and zinc
layer thicknesses. The magnetic principle is used to measure the combined paint/zinc
thickness over the ferrous substrate and the eddy current principle is used to measure
the paint thickness over the non-ferrous zinc coating. The zinc thickness is calculated
by subtracting the paint thickness from the combined paint/zinc thickness
measurement.
PosiTector
®
6000 FNDS probe
for Duplex Coatings
Addendum to Instruction Manual v. 7
How to Measure
The PosiTector
6000
powers up when the center navigation button is pressed.
To preserve battery life, the instrument powers down after approximately 5 minutes
of no activity. All settings are retained.
1. Remove the protective rubber cap from the probe.
2. Power-up the Gage by pressing the center navigation button.
3. Place the probe on the surface to be measured. When a measurement is calculated,
the Gage BEEPS and the measurement is displayed.
NOTE: A “---” dashed line value and a low tone indicates the Gage was unable to
calculate the zinc layer thickness
4. Lift the probe AT LEAST 2 inches (5 cm) between readings or leave the probe on the
surface in the same location for continuous measurements.
Verify accuracy on reference standards at the beginning and the end of each shift, or
if the gage is dropped or suspected of giving erroneous readings.
When enabled (default), the Gage will display two measurement values (as shown
above). To disable, uncheck
Duplex
within the
Setup
Menu. Alternatively, press the
Up navigation button to toggle Duplex On/Off (when Memory is OFF).
When disabled, the Gage will operate like a conventional combination ferrous/nonferrous instrument (similar to the PosiTector
6000 FNS
probe). Ideal for measuring
non-magnetic coatings over steel and non-conductive coatings over non-ferrous metal
substrates.
N = Paint Thickness
Zn = Zinc Thickness
The first time a part is measured, and any time the process changes, check zero on
both the bare steel substrate and on the uncoated zinc surface. Adjust if necessary
(see Calibration Adjustment).
Calibration Adjustment
Adjustment, or calibration adjustment is the act of aligning the Gage’s thickness
readings to match that of a known sample in order to improve the effectiveness of the
Gage on a specific surface or in a specific portion of its measurement range.
PosiTector
6000 FNDS
probes are factory calibrated and perform an automatic selfcheck each time a measurement is taken. For many hot-dip galvanized applications,
no further adjustment is necessary from the factory calibration. The symbol
disappears whenever a calibration adjustment is made.
F Zero Adjustment
Measure the uncoated steel substrate (if available). If the average of several “N”
readings is not within tolerance of “0”, perform an F Zero adjustment.
1) Select F Zero from the Cal Settings menu.
2) Press (+) to select the number of readings to be used to obtain an average, typically
3 to 10 readings. The greater the variation between readings, the more zero readings
should be taken to obtain an average.
3) Repeatedly measure the uncoated steel part. The Gage will wait two seconds after
placing the probe on the surface to allow the user to correctly position the probe. After
the last measurement, the Gage will calculate a Zero which represents the average of
all the F Zero readings taken.
Zn Zero Adjustment
Measure the unpainted zinc surface (if available). If the average of several “N” readings
is not within tolerance of “0”, perform an Zn Zero adjustment.
1) Select Zn Zero from the Cal Settings menu.
2) Press (+) to select the number of readings to be used to obtain an average, typically
3 to 10 readings. The greater the variation between readings, the more readings should
be taken to obtain an average.
3) Repeatedly measure the unpainted galvanized part. The Gage will wait two seconds
after placing the probe on the surface to allow the user to correctly position the probe.
After the last measurement, the Gage will calculate a Zero which represents the
average of all the Zn Zero readings taken.
N 1 Pt Adjustment
For rough zinc surfaces (i.e. zinc spray metallizing), it may be desirable to adjust the
Gage to a known thickness, such as a shim placed over the zinc, rather than adjusting
it to zero. This ensures the Gage measures the thickness of paint over the metallizing
“peaks”.
1) Select N 1 Pt Adjust from the Cal Settings menu.
2) Press (+) to select the number of readings to be used to obtain an average, typically
3 to 10 readings. The greater the variation between readings, the more readings should
be taken to obtain an average.
3) Repeatedly measure the known thickness reference on the unpainted galvanized
part. The Gage will wait two seconds between readings to allow the user to correctly
position the probe on the surface. After the last measurement, the Gage will calculate
and display the reading which represents the average of all the measurements taken.
If the expected reading is not obtained (within tolerance), lift the probe from the surface
and adjust the reading down (-) or up (+) to the expected thickness and press .
NOTE: The reference thickness should be similar to the expected paint thickness.
© DeFelsko Corporation USA 2016 All Rights Reserved
For more detailed instructions, see the included PosiTector
6000 Quick Guide.
PosiTector
6000 FNDS
probes are compatible with all PosiTector Advanced
models (serial numbers 730,000+) and Standard models with color display.
Probe Specifications
Mils Microns
Minimum Zinc Thickness 0.5 mil 13 µm
Paint Layer Accuracy
+/- (0.05 mil + 1%) 0-2 mils
+/- (0.1 mil + 1%) > 2 mils
+/- (1 µm + 1%) 0-50 µm
+/- (2 µm + 1%) > 50 µm
Zinc Layer Accuracy
+/- (0.1 mil + 1%) 0-2 mils
+/- (0.2 mil + 1%) > 2 mils
+/- (2 µm + 1%) 0-50 µm
+/- (4 µm + 1%) > 50 µm
For full specifications refer to defelsko.com/p6000/p6000_probe_details.htm
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