Linearity and Hysteresis Measurements

TM 11-6660-204-25

b. Linearity Measurements (Converter and Re-

(6) Adjust the REF. ADJUST control until

corder Combined). Compare the chart recording

the pen indicates 95 chart divisions.

obtained in a above versus the frequency input for

both the ascending and descending plot of fre-

8-13. Signal Voltage Variation Test for

quencies. The correct chart recording should be a

Converter and Recorder

value equal to the input frequency. The differ-

a. General. Turn on the equipment and allow

ence (spread) between the largest positive devia-

the equipment to warm up for 30 minutes.

tion from the correct reading and the largest neg-

Connect the radiosonde recorder with the asso-

ative deviation from the correct reading shall not

ciated test equipment as shown in figure 8-2.

e x c e e d 0.2 division (approximately .020 inch).

This linearity measurement includes the effects of

b. Procedure.

hysteresis.

(1) Adjust the TS-65C/FMQ-1 Frequency

Standard for a 10-volt peak-to-peak intput signal.

c. Hysteresis Measurements (Converter and Re-

(2) Place the SIGNAL SELECTOR switch in

corder Combined).

the SIG position.

(1) With the test configuration shown in

(3) Adjust the signal input frequency to 10

figure 8-2, apply a 10-HZ, 15-volt peak-to-peak

Hz.

signal to the recorder.

(4) Allow the pen to trace for 5 seconds to

(2) Depress the INTER S.C. -OUTPUT S.C.

obtain a stable line.

switch until the pen goes to zero. Release the

(5) Repeat steps (3) and (4) above, adjust-

switch and observe the pen. approach 5 on the

ing the signal frequency to each frequency given

chart from the lower value. Allow the pen to

in the table below.

record for 30 seconds.

(6) Adjust the frequency standard for a 20-

(3) Depress the REC. TEST switch until the

volt peak-to-peak signal voltage and repeat steps

pen goes to 95. Release the REC. TEST switch

(3) through (5) above.

and observe the pen approach 5 on the chart from

(7) Adjust the frequency standard for a 30-

the higher value. Allow the pen to record for 30

volt peak-to-peak signal voltage and repeat steps

seconds.

(3) through (5) above.

(4) The horizontal distance between the two

(8) Use the 20-volt signal recordings as a

traces (hysteresis) should not exceed 0.1 of one

r e f e r e n c e . The 10-volt and 30-volt recordings

chart division,

should not vary more than .1 division from the

20-volt recording for each of the corresponding

(5) Repeat the above procedure for 20, 40,

frequency inputs.

60, 80, 100, 120, 140, 160, 180, and 190 Hz.

Frequency

Chart Recording

Step

8-15. Speed of Response

a. With the radiosonde recorder and test equip-

120

ment in a room temperature environment and

160

warmed up for 20 minutes, connect as shown in

190

figure 8-1.

8-14. Linearity and Hysteresis

b. Rotate the SIGNAL SELECTOR switch to

Measurements

the S.C. position. Adjust for a zero chart record-

ing. Set the TS-65C/FMQ-1 for a 190 Hz input

a. General.

signal. Rotate the SIGNAL SELECTOR switch to

(1) Connect the recorder with the associated

SIG. Adjust the pen to indicate 95.

test equipment as shown in figure 8-2.

(2) With the SIGNAL SELECTOR switch in

c. When the pen is properly adjusted, operate

SIG. position, signal (approximately 25v peak-to-

the SIGNAL SELECTOR switch back and forth

peak) shall be applied in the sequence of 0, 10, 20,

between the SIG. and S.C. positions. Record the

40, 60, 80, 100, 120, 140, 160, 180, 190, 180, 160,

time for the pen to travel between zero and the 95

140, 120, 100, 80, 60, 40, 20, 10, and 0 Hz. Allow

division mark using a stopwatch. This time should

the recorder to print at each frequency setting for

not exceed 2 seconds.

at least 10 seconds.

Change 1

8-4