National Instruments USB-9211 Thermocouple Input Device

The NI USB-9211 (Part Number: 778976-01) is a 24-Bit Thermocouple Input Device with 4 channels. This device offers a USB interface with integrated signal conditioning. By design, the NI USB 9211 is comprised of two separate parts: the USB-9161 Carrier and the NI-9211 module. However, the carrier and the module are provided in disengaged form. The user can easily insert the thermocouple input device into the carrier without using any tools. The USB-9211 device can also be mounted to a panel.

Every channel has an impedance between the TC- and COM terminals, as well as between the TC+ and COM terminals. During operation and data acquisition, every channel is filtered before being sampled through a 24-bit Delta-sigma ADC. A current source is provided between the TC+ and TC- terminals. When an open thermocouple is linked to a channel, a full-scale voltage is forced through TC+ and TC- terminals by the current source. For most applications, the offset and gain errors resulting from thermocouples source impedance can be deemed as negligible while operating with thermocouples connected.

For measuring offset error, the NI USB-9211 comes with an internal autozero channel. Users can use the autozero channel to the read the offset error if the device is to be operated in less than 15 °C and more than 35 °C ambient temperature. The autozero channel always remains enabled. Additionally, one internal cold-junction compensation channel is available. The National Instruments USB-9211 is compatible with a broad range of thermocouples such as; S, T, N, J, K, B, etc.

USB-9211 Obsolete Status has been declared by National Instruments, but the device will still be available for purchase and repairs by Apex Waves.