The Yocto-PT100 is a USB temperature sensor. This is the most accurate USB temperature measurement device that we offer. The module uses an external PT100 probe (not included) to make instant temperature measurements, and can also record measures on a built-in flash memory to read them later on through USB. A PT100 probe is used to measure the temperature at any specific place, including in a liquid, with a very high stability and a high accuracy(sensibility up to 0.01°C and accuracy up to 0.03°C at 0°C when using a PT100 conforming to IEC 60751 DIN 1/10 B standard). It is particularly well suited for applications such as laboratory measurements, etc.
The Yocto-PT100 can be used with PT100 probes using 2, 3 or 4 wires. The type of connection is setup in software. To reach the highest accuracy, a 4-wire probe should be used. 3-wire probes are reasonably accurate and not too much affected by wire lengths, contrarily to 2-wire probes which are the least accurate and very sensitive to wire length.
The Yocto-PT100 features a built-in galvanic isolation between the USB control part and the PT100 measure circuit. It is therefore possible to use non-insulated PT100 probes, which are often more reactive and less expensive,
Given the number of variants of PT100 probes and their prices, the Yocto-PT100 does not include any probe. The probe must be purchased separately at a specialized shop.
This device can be connected directly to an Ethernet network using a YoctoHub-Ethernet, to a WiFi network using a YoctoHub-Wireless-n and to a GSM network using a YoctoHub-GSM.
USB cables and enclosures to be ordered separately.
This yocto-pt100 can be configure to measure a SPRT with constants that corresponse to ITS-90?
@jjarandato There are 3 aspects to this question:
1) the absolute precision
2) the resistance range
3) the format of correction factors:
Regarding 1, the absolute precision of this device has been verified to match the requirements for Secondary SPRTs (0.03°C), but we have not checked for a higher precision. If you really need 0.001°C, you will probably need a more precise device, I doubt we can be as precise in absolute value.
Regarding 2, this device applies the resistance-to-temperature function for PT100. If you need to use SPRT in the ~25 Ohm range, you could work from the measured resistance value (without using the internal mapping), but you will be out of the sweet spot of the device for resistance measurement and will probably loose a bit of precision
Regarding 3, the device features a built-in mechanism for 5-points linear calibration function, but not another more specific format
I'm curious if its possible to use your PT100 with 44212EC sensor without major modifications and to still expect 0.1C accuracy.
@tetaran: The 44212EC sensor is not a PT100, it is a combination of thermistors using different resistance values. It might be possible to read it using a Yocto-Thermistor, but I am not even sure as I have not digged into the magic of this thermilinear network...
Documenting a solution to the 1386 error when using DLL with LabVIEW : This error (1386 when using the LabVIEW VI with the DotNetProxy DLL) is well known issue. Using an application other than Windows unzip tool ( like WinZip or 7zip) to decompress the downloaded files results in a working DLL.
Otherwise, in my case the solutions given in the documentation did not work.
Hi, I would like to ask what is the maximum resistance possible in the current circuit for the Pt100 module? I would have high resistance cables ~ 500 Ohm (corresponding to your R1 and R4 in the manual. Plus the Pt100 itself for sure. Is 600 Ohm in that circuit OK?
@tkoettig: if you use a 4-wire Pt100 probe, this should be no problem. But you should really use a 4-wire probe.
Hi, is it at all possible to modify the device to achieve a higher maximum temperature measurement? I would like to be able to reach at least 450 degrees C.
@AshbyHilton: Good question... I double-checked the the hardware and the code, and everything is in place to cover the full Pt100 range up to 850°C. Unfortunately I can't remember why we did limit its range to 325°C when we brought the product to market, but I suppose that when we did create the device, we did not have the proper equipment to test accuracy higher than 325°C.
However I just did a test using a calibrated Pt100 source with a wide range, and the Yocto-Pt100 does indeed report proper readings up to the top. So I have now officially upgraded the supported measurement range, which should fit your needs :-)
Thanks for the reply, that's very helpful!
Can this board and a PT100 be used as an accurate reference for calibrating other - less accurate - Yoctopuce devices, like Yocto-Meteo-V2, Yocto-Thermocouple and Yocto-MaxiThermistor, or should I look into other devices to use as my reference?
I am not looking into resolutions higher than 0.1°C, but currently I am observing a 5°C gap between an old fashioned thermometer and my Yocto-Meteo-V2 and Yocto-Thermocouple (Yocto-MaxiThermistor not converted to degrees yet), which even if the old fashioned thermometer does not necessarily show a great absolute accuracy, sounds too high a deviation to assume the Yocto ones are closer to reality (my guess is they are all off and the real value is somewhere in between, 5°C of variation at room temperature is a huge gap).
@Mat F: Generally speaking, yes, you could use a Yocto-Pt100 to calibrate other less precise sensors such as Thermistor. But as for the Yocto-Meteo-V2, a 5°C gap cannot come from a bad calibration, as the sensor is factory-calibrated by Sensirion and has a much better absolute precision than this. Most likely you are rather experiencing the issue described in this blog post: https://www.yoctopuce.com/EN/article/how-to-correctly-measure-ambient-temperature