HP 11049A, Руководство по эксплуатации и обслуживанию, Страница: 16 / 19

Model 1l049A
d. Vary Rl resistors to achieve a null indication
on null meter. Maximum deviation from null
should be as follows.
1l049A
11050A
1l051A ±1. 25 mV
±O. 375 mV
±0.15 mV
A high value carbon resistor maybe added in
parallel with Rl as a final adjustment.
34. INSTALLATION OF THERMOELEMENT, Rl, AND
R2.
35. The spatial orientation of the components within the
thermoelement is critical. Improper placing of the
components nmy cause serious degradation of the
higher frequency response. Figure 9 shows the proper
component placement for each of the comp'onents in
each thermal converter.
36. Observe the following precautions when installing
replacement thermoelement and Rl and R2.
Page 10
USE AN ADEQUATE HEAT SINK WHEN
SOLDERING CONNECTIONS TO THERMO­
ELEMENT. EXCESSIVE HEATING WILL
CHANGE THERMO ELEMENT CHARAC­
TERISTICS.
a. Keep all leads as short as possible.
b. Make sure that component mounting matches
that shown in Figure 9.
c. Avoid bending thermoelement leads any more
than is absolutely necessary. Excessive bending
may weaken glass seal and reduce isolation.
d. Red (positive) lead should be connected to
thermoelement output lead with red dot.
37. REPLACEABLE PARTS.
38. Figure 10 shows the replaceable parts for the
thermal converters. Included with each part is its
-hp- part number, description , manufacturer,
manufacturer! s part number, and total quantity.