Extraction Heater

TM 5-6640-212-142

NOTE

2-30. Refractometer.

a. Description.

The ink level should be kept as low as

(1) The refractometer (fig. 2-28) is designed to

possible for cleanest lines and

comply with the requirements specified in ASTM Method

shortest drying time.

D1218 (TM10-1167) and FTMS 791, Method 5340. It is

stowed in cabinet K3 (figs. 1-2 and B-16). The

refractometer is used to determine the refraction index of

2-29. Extraction Heater. The extraction heater is

percent of total dissolved solids.

The instrument

stowed in cabinet F1 (figs. 1-2 and B-12). It is a

consists of a refracting prism system, a scale, a

thermostatically controlled hot plate with four sets of

compensation system consisting of Amici prisms which

extraction clamps supported on four vertical rods

permit the use of white light, and a telescope with

attached to the back of the unit. The clamps and rods

crosshairs which permit the borderline of total reflection

are stored in drawer E2 (fig. B-12). A repeatable heat

to be observed and set precisely. The refracting prism is

control and a percentage timer provide accurate and

fixed and horizontal and the observing eyepiece is

reproducible temperatures over the entire working

directly above the measuring prism. A pivotal mirror is

surface within a range of 150 degrees F to 800 degrees

used to move the total reflection dividing line. The index

F (66 degrees C to 427 ,degrees C). The extraction

scale is attached to the pivotal mirror. The single

heater may be used as a Utility hot plate by removing the

eyepiece is used to observe both the total reflection field

extraction clamp rods.

and the scale

Figure 2-28. Refractometer

2-49