Measurement Computing USB-TEMP, User Manual

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USB-TEMP User's Guide Specifications
5-5
Table 5-8. Typical thermistor resistance specifications
Temp 2252 Ω
thermistor
3000 Ω
thermistor
5 k Ω
thermistor
10 k Ω
thermistor
30 k Ω
thermistor
-40 °C 76 k Ω 101 k Ω 168 k Ω 240 k Ω (Note 12) 885 k Ω (Note 12)
-35 °C 55 k Ω 73 k Ω 121 k Ω 179 k Ω 649 k Ω (Note 12)
-30 °C 40 k Ω 53 k Ω 88 k Ω 135 k Ω 481 k Ω (Note 12)
-25 °C 29 k Ω 39 k Ω 65 k Ω 103 k Ω 360 k Ω (Note 12)
-20 °C 22 k Ω 29 k Ω 49 k Ω 79 k Ω 271 k Ω (Note 12)
-15 °C 16 k Ω 22 k Ω 36 k Ω 61 k Ω 206 k Ω (Note 12)
-10 °C 12 k Ω 17 k Ω 28 k Ω 48 k Ω 158 k Ω
-5 °C 9.5 k Ω 13 k Ω 21 k Ω 37 k Ω 122 k Ω
0 °C 7.4 k Ω 9.8 k Ω 16 k Ω 29 k Ω 95 k Ω
Note 12:
Resistance values greater than 180k ohms cannot be measured by the USB-TEMP in the
thermistor mode. The 180k ohm resistance limit includes the total resistance across the
current excitation (±Ix) pins, which is the sum of the thermistor resistance and the lead
resistances.
Note 13:
For accurate three wire compensation, the individual lead resistances connected to the ±Ix
pins must be of equal value.
Throughput rate
Table 5-9. Throughput rate specifications
Number of Input Channels Maximum Throughput
1 2 Samples/second
2 2 S/s on each channel, 4 S/s total
3 2 S/s on each channel, 6 S/s total
4 2 S/s on each channel, 8 S/s total
5 2 S/s on each channel, 10 S/s total
6 2 S/s on each channel, 12 S/s total
7 2 S/s on each channel, 14 S/s total
8 2 S/s on each channel, 16 S/s total
Note 14:
The analog inputs are configured to run continuously. Each channel is sampled twice per
second. The maximum latency between when a sample is acquired and the temperature
data is provided by the USB unit is approximately 0.5 seconds.