Máy đo độ dày sơn - PAINT BORER 518 MC | Erichsen

Máy đo độ dày sơn - PAINT BORER 518 MC | Erichsen

The Measuring Principle

The PAINT BORER 518 MC operates in accordance with the standardised wedge cut method in which the specimen is cut at a defined angle. From the projected width of the cut face the layer thickness can be calculated making use of a simple geometrical relationship. With Model 518 MC the damage to the coating is limited to a small conical hole as illustrated in the sectional view. In the measuring microscope a system of concentric circles is visible and from the difference in the radii of the circles which are measured using the measuring microscope, the film thickness can be calculated by multiplying with a known factor.

The Measuring Instrument

The PAINT BORER 518 MC is a very compact instrument. All the principal components - the drilling device, the measuring microscope, the specimen illumination and the battery - are enclosed in a sturdy housing. A slide moving on horizontal slide-ways houses the drill and microscope and gives the PAINT BORER 518 MC its particular feature: the Instrument itself does not have to be moved for measuring after drilling.

The drill is spring mounted in the slide so that it can be pressed down onto the specimen with minimum force, the drill being switched on automatically when this is done. The carbide drills are easy to exchange and supplied with different accurately maintained cutting angles for 3 standard measuring ranges. The measuring microscope with a magnification factor of 50 has a measuring scale with 100 lines so that a resolution of 1% is obtained irrespective of the measuring range.

The light button on the backside of the PAINT BORER 518 MC can be set for either continuous light as well as three levels of illumination or interrupted illumination to prolong battery life. A 9-volt rechargeable battery is employed; mains operation with the charging unit is possible.

Due to the mobility of the microscope into two directional axes (turned by 90° from one another) and with the possibility of turning the scale, the PAINT BORER 518 MC is especially suitable for the evaluation of elliptical holes that arise with curved/ tilted specimens.

The Operation

The coating thickness measurement with PAINT BORER 518 MC is very simple: Apply a contrast mark (felt tip pen) and place the measuring instrument on the specimen. Move the drill into position over the test point and lower it causing the motor to switch on. Drill the coating through to the substrate. Move the microscope over the hole and switch the lamp on. Count the number of scale marks between the base material and the contrast mark and multiply this value by the scale factor which gives the measuring results.

Special applications (individual layers of a multi-layer system, measurements on curved/tilted specimens) are dealt with in the operating instructions.

ISO 19399, ISO 2808, ASTM D4138, ASTM D 5796

Specimen platform for fixation/measurement of small parts consisting of: Base stand, counter plate with drill window, inflatable rubber impression ball with ergonomic Peleus ball and 3 flexible hard foam cushions.

The small specimen to be measured is fixed after manual positioning on the flexible hard foam cushion under the drill window of the counter plate.

Minimum sample size for small parts: à 17 mm (whether round, square

or otherwise shaped; has to be considered in relation to the drilling and measuring opening of the specimen table I)

The circular executed drilling and measuring opening of the counter plate has a diameter of 15 mm.

Its edge holds the flat surface of the small specimen to be measured, pressed from below, at the correct height level for drilling as well as for focusing and measuring by the measuring microscope.

The upper counter plate with drill window can also be used separately as a free positioning aid (just loosen 4 screws) to set up the PAINT BORER 518 MC or 518 USB on surfaces that would otherwise not be comfortable to set up resp. use due to their too small dimensions (drilling & measuring).