13
4.5.3
Waveform Checks For Model 871A
Waveform Checks: Referenced To
È
(Digital Ground)
Clock
U111, Pin 3
360 kHz, 5V pp Square Wave
A/D Clock
U112, Pin 5
40 kHz, 5V pp
Rectangular Wave
Ref. Clock 1
U102, Pin 9
60 kHz, 5V pp
Rectangular Wave
Ref. Clock 2
U102, Pin 14
6 kHz, 5V pp
Rectangular Wave
Backplane
U101, Pin 20
50 Hz, 5V pp
Rectangular Wave
4.5.3
Waveform Checks For Model 872A
Waveform Checks: Referenced To
È
(Digital Ground)
Clock
U111, Pin 3
360 kHz, 5V pp Square Wave
A/D Clock
U112, Pin 5
40 kHz, 5V pp Rectangular Wave
Ref. Clock 1
U102, Pin 9
90 kHz, 5V pp Rectangular Wave
Ref. Clock 2
U102, Pin 14
9 kHz, 5V pp Rectangular Wave
Backplane
U101, Pin 20
50 Hz, 5V pp Rectangular Wave
SECTION
5
SPECIFICATIONS FOR MODEL 871A AND
MODEL 872A
GENERAL
THERMOCOUPLE INPUTS:
Two, switch selected
ACCURACY:
±0.25% of r1ºC (0.25% ±1.8ºF) for
one year, 64º to 82ºF (10º to 28ºC) ambient
EXTENDED SPAN ACCURACY:
-40º to -55ºC: +2ºC, -0ºC
REPEATABILITY:
±0.2ºC Typical (one hr., constant
ambient temperature)
TEMPERATURE COEFFICIENT:
64º to 82ºF (18º to 28ºC); Less than
±(0.025% of r0.1ºC) 1ºC; for
temperatures less than 64ºF (18ºC) or
greater than 82ºF (28ºC)
MAXIMUM ALLOWABLE TC
INPUT OVERLOAD:
35Vdc (42 V peak AC)
NORMAL MODE REJECTION
RATIO:
Greater than 45 dB at 50 and 60 Hz
COMMON MODE REJECTION
RATIO (1K
Ω
UNBALANCE):
Greater than 120 dB at dc, 50 and 60 Hz
DISPLAY:
3
¹⁄₂
digit LCD, 0.6" height. Polarity and
decimal point indication
MAXIMUM COMMON MODE
VOLTAGE:
500 V
