ANALYTICAL BALANCE - TM-5-6640-213-140093

TM 5-6640-213-14

TS 6640-213-14/3-3

Adjusting Vacuum Level by Turning Valve Stem of

Inlet Regulator Valve.

3-6.

ANALYTICAL BALANCE.

Calibration Procedures.

(1) Zero the balance by rotating the weight control knob

(7, fig. 2-6)' until the macro weight counter (6) shows zero; and then

rotating the micrometer drum knob (3) until the optical weight

counter is zeroed, or until the micrometer line is as nearly on zero

as the mechanical lash in the knob control will allow; and finally,

rotating the zero control knob (1) until zero shows on the micro

weight counter (4). If the exact zeroing of the micro weight counter

cannot be achieved, "zero-point adjust" the balance as noted in

paragraph (4) below. If the range of the zero control knob does not

permit zeropoint adjustment; the range must be readjusted as noted in

paragraph (5) below. If the macro weight counter cannot be zeropoint

adjusted, the range of the weight control knobs must be adjusted as

described in paragraph (6) below.

(2) Scale illumination can be adjusted by assuring proper

bulb contact to provide maximum bulb brightness. If additional

illumination is desired, remove the hood and loosen the knurled head

screw (19, fig. 3-6) which holds the cover on the recessed lamp

housing in the left rear of the balance. Slide the cover from side

to side and up and down until the desired illumination is obtained.

Tighten the knurled head screws firmly while holding the cover in

position. A replacement bulb is available and is stored in the lower

spare mount.