Note:

Owing to the chip shortage, we are currently out of stock on this product, and may not have more for several months.

What is it?

Temperature sensor (-50°C to +200°C) w. 18-bit ΔΣ ADC; comes fully assembled, ready for use.

Why did you make it?

Originally developed for monitoring process temperature in small physical plants; several wired temperature sensors are connected to a Raspberry Pi, which can in turn connect to a network and be used to monitor the plant. This device can also become part of a closed-loop feedback control system.

What makes it special?

Logging temperature allows traceability of processes, so it/they can be verified as having run as required. Up to four sensors can be daisy-chained, allowing monitoring at several different points in the plant; easy to use, software is available as well (written in Python3 for Raspberry Pi).

Although the temperature sensing range is quite wide, the PCB itself is limited to the range of its components (-40°-125°C). The range specified above covers the range over which the amplifier will accurately transform the Platinum RTD's resistance into voltage. Different temperature ranges are available via gain resistor changes.

The ADC is available with four different I2C addresses, allowing several points to be measured simultaneously.

Sensors can be ordered with either a surface-mounted sensing element, or a through-hole element on wires. The SMD version is compact and convenient compared to the wired sensor version, however the wired unit is more accurate as it's less subject to self-heating from the PCB; also, whereas the surface-mounted sensor's range is limited to the -40°C to +125°C range of the components on the PCB, the sensing element itself has a range of -50°C to +500°C. As impressive as that looks, 500°C will melt solder, so running the sensors up to this temperature is inadvisable.