Keithley 7711, Руководство пользователя

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Additional measurement uncertainty
Table 7 lists additional uncertainty to the published specifications for the Model 7708. Other modules, such as the Model 7700
(which measures thermocouple temperature), are also affected by this heat but are still within published specification. The
amount of uncertainty is dependent on:
• Model 7711/7712 slot location
• The amount of time the channel is programmed as an output
• Which other model 77XX module(s) are being used
The listed uncertainty in Table 7 is listed for channels 4 and 8 closed. The uncertainty is linear—for each channel programmed
as input or off, there will be approximately 25 percent reduction in the listed on uncertainty. Table 8 lists the percentage of
additional uncertainty for specific channel pairs closed.
Table 7
Additional uncertainty for Model 7711/7712
Thermocouple Range 7708
J -200 to 0˚C
0 to +768˚C
K -200 to 0˚C
0 to +1372˚C
0.4
N -200 to 0˚C
0 to +1300˚C
0.75
0.15
T -200 to 0˚C
0 to +400˚C
0.4
E -200 to 0˚C
0 to +1000˚C
0.15
R 0 to +400˚C
0 to +1768˚C
1.5
S 0 to +400˚C
0 to +1768˚C
1.5
B 350 to 1100˚C
0 to +1820˚C
2.4
0.6
Notes:
1. The above listed uncertainties are guaranteed by design for thermocouple types J, K, N,
T, E, R, S, B.
2. When the Model 7711/7712 and Model 7708 are used together, the Model 7711/7712
must be installed in the lowest numbered slot.
For example: Model 2700/2701: 7711/7712 in slot 1, 7708 in slot 2
Model 2750: 7711/7112 in slot 2, 7708 in slot 3