POLARIMETER-POLARISCOPE MODEL 204
This Instrument may
be used in any position from vertical to the horizontal.
Analyzer is mounted within calibrated circle reading clockwise from 0°
to 180° and counter-clockwise from 0° to 180°.
For use as a polariscope,
the analyzer is set to zero. The polarizing field is a typical red-purple
and strain is seen in characteristic colors for tension and compression.
For use as a polarimeter,
the sensitive tint plates are swung out of the optical path by a finger
movement; this movement automatically brings the quarter wave plates into
the optical path. The polarizer now appears as a typical dark extinction
field and a strained glass specimen is seen as a shaded black to white
area. To measure this strain, the calibrated analyzer is rotated until
the light area turns to maximum darkness.
Note: This instrument
is designed to meet ASTM specifications.