Throughput rate – Measurement Computing WEB-TC User Manual
Page 30
WEB-TC User's Guide
Specifications
30
Note 3:
Thermocouple measurement accuracy specifications include polynomial linearization, cold-junction
compensation and system noise. These specs are for one year, or 3000 operating hours, whichever
comes first, and for operation of the WEB-TC between 15 °C and 35 °C after 30 minute warm-up. The
tempco should be applied to the accuracy specifications for operation at an ambient temperature
outside of the 15 °C and 35 °C range. There are total of four CJC sensors, two per side of the module.
Each CJC sensor is dedicated to one of the four channel pairs. The accuracy listed above assumes the
screw terminals are at the same temperature as the CJC sensor. Errors shown do not include inherent
thermocouple error. Contact your thermocouple supplier for details on the actual thermocouple
accuracy error.
Note 4:
Thermocouples must be connected to the WEB-TC such that they are floating with respect to AGND
(pins 9, 19, 28, 38, 48). The WEB-TC AGND pins are isolated from earth ground. You can connect
thermocouple sensors to voltages referenced to earth ground as long as the isolation between the
AGND pins and earth ground is maintained.
Note 5:
When thermocouples are attached to conductive surfaces, the voltage differential between multiple
thermocouples must remain within ±1.4 V. For best results, we recommend using insulated or
ungrounded thermocouples when possible.
Throughput rate
Table 5. 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 6:
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
Ethernet unit is approximately 0.5 seconds.