Calibration Types; Calibration Considerations; Preparing For Calibration - Extech Instruments CG204 User Manual

Calibration

Calibration Types

The meter is factory calibrated before shipment to the customer; however the customer
should perform a zero calibration and a multi-point calibration before any critical
measurements are taken. The calibration options are listed below. Read the description
for each and select the best match for a given application.
1. Zero Point Calibration: Perform before each measurement session.
2. One Point Calibration: Use for high accuracy with repeated tests on a constant
coating thickness.
3. Multi-Point Calibration: Use for high accuracy within a known range of coating
thickness.
4. Calibration for shot-blasted surfaces.

Calibration Considerations

The calibration sample must correspond to the product sample in the following ways:
• Curvature radius
• Substrate material properties
• Substrate thickness
• Size of measurement area
• The point at which the calibration is made on the calibration sample must always
be identical with the point of measurement on the product itself, especially in the
case of corners and edges of small parts.
To achieve the highest measurement accuracy, perform several calibrations in succession
(for zero values and calibration film values).

Preparing for calibration

1. Clean the probe tip (grease, oil, metal scrap, and the slightest impurity will affect
measurement and distort readings).
2. Switch the meter ON (at a 4" [10cm] minimum distance from any metal).
3. Ready the supplied metal substrate samples and necessary films (supplied
calibration reference films).
4. Set the meter to:
a. DIR: (MENU-OPTIONS-Working Mode-Direct)
b. CONTINUOUS: (MENU-OPTIONS-Measure Mode-Continuous mode [flashing
units indicator] )
c. MAX: (MENU-OPTIONS-LCD Statistic-Maximum).
5. The meter is now ready for calibration.
www.burntec.com
8 CG204-EU-EN V2.1 3/11