Scratch Adhesion Mar Tester (S.A.M. Tester)

1. First insure that the instrument fulcrum is positioned for the required range, either 20 to 250 grams or 200 to 2500 grams and set the desired loading on the load control dial.
2. Place the lower edge of the instrument against the test surface with sufficient pressure to insure uniform contact.
3. While held in this position, draw the instrument in a direction away from the “blade”.
4. Observe the nature of the mark left by the “blade”, if any. The test may then be repeated at a different setting on the control dial.

Balance Beam Use

1. Prior to the use of the S.A.M. Tester fitted with the Balanced Beam stylus adapter, insure that the stylus of choice is installed and that the fulcrum is in the correct position for either the high or low range.
2. Set the desired loading on the stylus by loosening the locking nut and rotating the dial to the desired value.
3. Retighten the locking nut taking care not to change the set reading on the dial.
4. Hold the lower edge of the instrument against the test surface with enough force to overcome the loading on the stylus.
5. Retaining this force, move the instrument along the test surface in the direction at a rate of 0.5 to 1.0 inches per second.
6. If the coating is not damaged in the initial test, continue testing using successively higher loading on the stylus until the desired results of coating failure is observed.
7. Both the loop and the needle stylus are produced from 1/16 inch tool steel, heat treated to a hardness of Rockwell C 58 to 60 and then polished. The loop stylus has an outside radius of 0.128". The needle stylus has a 1.00mm diameter tip.
8. Warning: Do not interchange either the loop or needle stylus between the Balanced Beam Tester (Model 2197A) and the S.A.M. Tester. Overall length of the stylus for the Balanced Beam Tester (Model 2197A) is 1.000" with an extension beyond the fixture of 0.375". Overall length of the stylus for the S.A.M. Tester is 0.440" with an extension beyond the adapter of 0.190".

CrossCut Adhesion Use

1. Prior to use of the S.A.M. Tester fitted with the adhesion cutter attachment, insure that the cutter of choice is installed and that the fulcrum is in the correct position for either high or low range.
2. Set the desired loading on the cutter by loosening the locking nut and rotate the dial to the desired value.
3. Retighten the locking nut taking care not to change the set reading on the dial. Hold the lower edge of the instrument loading handle against the test surface with enough downward force to overcome the loading on the cutter.
4. Retaining this downward force, move the loading handle along the test surface making a trailing pattern with the cutter.
5. Repeat this cutting motion at 90 degrees to the first cut. (Note that the lower front surface of the instrument is undercut so as not to disturb the surface in the area of the first cut.)
6. Evaluate results obtained as prescribed in ASTM Standard D 3359, Method B.
7. Note: The cutter may be loaded in two different ranges: 20 to 250 grams and 200 to 2500 grams. If operating in the low range, divide the gram force required on the cutter by 10 and set the resultant value on the adjusting knob which has 25 divisions. If operating in the high range divide the required load by 100. It is most difficult when using the cutters in the standard handle to obtain uniform loading across the width of the cutter. Such uniform loading is required if reproducible results are to be obtained. The reasons are the same as given above for overall loading of the cutter. The adhesion cutter controller insures uniform loading from side to side of the cutter. The cutter attachment is secured to the lever arm of the controller by a single shoulder bolt and is free to rotate on this bolt. Therefore, the cutter is self aligning on the test surface. Also, for reproducible results, the face of the cutter must be held at 90 degrees to the test surface during its movement on such surface. An angle greater than this will cause the cutter to “ski” to the top of the coating while an angle less than this will cause the cutter to dig deeper.

Important Instructions for Changing Range of Tester

1. It is set to operate in the high range (200 to 2500 grams).
2. To set the handle to operate in the low range (20 to 250 grams), loosen the lock nut, set the control dial at minimum and retighten the lock nut.
3. Remove the Allen shoulder bolt from position “C” and place it in opening “B” while moving the cutter arm up and down for an easy fit.
4. Remove the shoulder bolt at position “A” and place it in the opening at “C”.
5. After setting the desired load on the control dial, the handle is ready for use in the low range.
6. Reverse this procedure to restore high range operation after setting the control dial at minimum.
7. (Caution: Do not remove the other shoulder bolts as interior components will drop out of place. Do not overtighten the shoulder bolts as the threads will be stripped from the nylon handle.)