The BK Recorder defines four stages in the drying process by using moving needle.
which travel along a coated glass test strip

* Defined Four Stage in the Drying Process
1) 1st Stage : the time taken for the solvent to evaporate.
2) 2ed Stage : an indication of the sol-gel transition zone.
3) 3rd Stage : an interrupt track, the surface-dry time.
4) 4th Stage : the final dry time, the needle no longer penetrates the film.
* The BK6 and BK10 Recorders have independently operating pairs of tracks allowing tests
to be made at different start time. * Brass : 5 g ,
* Glass Strips : 6 ea, 300×25 mm * 240V, 50Hz
* For other modes please specify BK type, motor speed and voltage/cycles required.
* Conformed to ASTM D5895 Test Method A.