PT100 RTD Temperature Sensor Explained with Error Compensation
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- Опубліковано 24 сер 2024
- In this video, PT100 RTD Resistance Temperature Sensor and Detector Circuit is Explained with Error Compensation to compensate for the effect of second order non-linearity of the RTD Platinum Temperature Sensors. PT100 is a positive temperature coefficient resistor whose value in Ohm changes as a functional of its temperature in the form of 100*[1+alpha*T+beta*T^2]. This circuit cleverly utilizes a weak positive feedback via a large potentiometer to counteract and compensate for the second order nonlinearity that depends on beta temperature coefficient. The analysis is provided in this video to compute the value of components to realize a linear variation of output voltage as a function of RTD resistor temperature. Two Zener diodes are carefully selected at the supply side to guarantee stable supply voltage with near zero temperature dependency.
hi sir !. me again. I got into the time machine and watched older videos on your channel. There I found information about NIC and GIC, after watching the videos I was able to understand that the first stage in capacitance multiplier used by the Thurlby Thandar TG-502 generator was a negative capacitive impedance converter and the second stage was a simple gain-scalable amplifier with current boosting at the output. In this way I was finally able to obtain the characteristic equation of the circuit and confirm my conclusions through LTspice. Thank you very much for all the contribution of your channel, now I can understand how gyrators work in audio pedals, exponential voltage to current converters in VCOs and NICs and GICs and many other interesting circuits such as analog multipliers.
Hi Luis, thank you for your comments. Happy to hear that the Capacitor multiplier videos were helpful. Thanks for sharing the good news that you have been able to analyze and understand how Gyrators work. Here are a few related circuit videos: GIC and NIC Impedance Converter with Op Amp ua-cam.com/video/o6l_wztCACQ/v-deo.html
Gyrator Op Amp Circuit as Impedance Converter Explained ua-cam.com/video/jPudh9yqDH4/v-deo.html
Best wishes!
Your work is amazing. Wish videos were slightly shorter!
@mostafanfs Thank you! Glad that you like this channel. I'd like to but there are many requests for detailed explanation. For more interesting circuits please browse the ua-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html playlist of 200+ circuit videos.
Thank you for each analysis video of your creation. I appreciate the quality of analysis you create in each presentation, I have learned a lot from the mechanism you use. I would like if at some point you have the possibility of analyzing the capacitance multiplier used by the Thurlby Thandar TG-502 generator. I can't find the equation that describes the circuit. I have watched your videos on the subject over and over and over again, but I get stuck when it comes to analyzing the impedances. I have no knowledge in the area of Laplace. Thank you for all the invaluable contributions you make to your followers. Postscript: I use a translator, apologies for the poor use of language
You are very welcome! Glad that you like my channel and glad that these circuit videos have been helpful. I hope that you find helpful the following two videos about capacitance multiplier circuit:
Capacitor Multiplier Op Amp Circuit: How does it work? ua-cam.com/video/AwFvmSVNDrU/v-deo.html
Variable Capacitance Multiplier Design with Op Amp ua-cam.com/video/apFyV9BgGjM/v-deo.html
I hope this is helpful
Absolutely brilliant channel! Very good explanations of any circuit. Thank you for sharing your knowledge with us. I personally appreciate it very much. I wish your channel stable growth in subscribers.
@@fxsurgeon You are very welcome! Glad that you liked this PT100 RTD Amplifier video. Thanks for the comment and your kind words. 🙏
PHENOMENAL
@@MrHeatification Thank you very much. Glad that you liked this Temperature Sensor Amplifier video. I hope you also enjoy the following related videos: Thermometer Circuit Design with Op Amp and BJT transistor ua-cam.com/video/55YsraFE0rg/v-deo.html
Thermometer Sensor Circuit Explained ua-cam.com/video/5jmbZ9ak6EI/v-deo.html
and EKG ECG Amplifier with Right Leg Drive Explained ua-cam.com/video/1c7KGXPs4do/v-deo.html ... Thanks again 🙏
thank you for sharing
My pleasure. Glad that you this Temperature Sensor Amplifier video is useful. Here are a few related videos: Thermometer Circuit Design with Op Amp and BJT transistor ua-cam.com/video/55YsraFE0rg/v-deo.html
Thermometer Sensor Circuit Explained ua-cam.com/video/5jmbZ9ak6EI/v-deo.html
I hope these videos are interesting as well.
Hello Prof., I understand that you are confident that the resulting parameters for RF, RP and R2 will produce a close to ideal curve and it seems reasonable given the path taken to compensate for the 2nd order characteristics. Do you ever validate your results in the real world?
@@fredflickinger643 Glad that this video is useful. Thanks for your interest and question. Please feel free to share your simulation results or observations 🙂
In case interested, here are a few related sensor amplifier videos: Thermometer Sensor Circuit Explained ua-cam.com/video/5jmbZ9ak6EI/v-deo.html
Strain Gauge Wheatstone Bridge Instrumentation Amplifier Explained youtu.be/io1yBcC
Thermometer Circuit Design with Op Amp and BJT transistor ua-cam.com/video/55YsraFE0rg/v-deo.html
How could I design a power supply circuit for supplying square wave pulses for electrochemical purposes?
@TeslaFactory The design of Square wave oscillator with operational amplifier is discussed in the ua-cam.com/video/vuMfW3U9WzY/v-deo.html video. For more examples see the ua-cam.com/play/PLrwXF7N522y4ee_0GL2EdguM-kLtJPxpU.html signal and waveform generator circuits playlist.
Could use one BZX55C5V1
Thanks for the 5.1 volt Zener Diode suggestion BZX55C5V1. While it has a low TC (Temperature Coefficient) of between +/- 0.02% per degree junction temperature change, it's TC is still 7-8x larger than the TX of series of 3.9v and 4.3v Zener Diodes recommended in the video. Thanks though for the good suggestion. 👍
@@STEMprof I looked at the TC values for the zeners in the video and the Vishay data sheet lists the TC as "typical" values, so the range is unknown.
@@h7qvi Good point. That's also needed to be taken into account.
This is an extremely complicated and over-engineered circuit, which also misses the biggest error root causes.
Precise temperature measurements with a PT100 requires at first a 4-wire measurement, i.e. separate current and voltage lines, and an offset compensation to eliminate thermal e.m.f.s.
All this calculus is too theoretical.
Thanks for your interest in this video and sharing your thoughts. Temperature Compensation and linearization are discussed in the video. Here are a few related examples: Thermometer Sensor Circuit Explained ua-cam.com/video/5jmbZ9ak6EI/v-deo.html
Thermometer Circuit Design with Op Amp and BJT transistor ua-cam.com/video/55YsraFE0rg/v-deo.html
I hope these circuits are interesting as well.
Actually that project is "a ready to use with 3 (or 4) wires" of Pt100
3 wires: zero (GND) wires left as it is. Then, on the plus (high side) one wire , the supply, current wire - goes to R1, the sensing, voltage wire goes to + input of the op-amp.
4 wires: plus, high side as with 3 wires. Low side (GND): current wire goes to local GND of "two Zener diodes" (4V3 low pole) and sensing wire goes to local GND of 1K resistor.
"local GND" means as close to GND of 4V3 Zener diode as possible and for 1k resistor as close as possible to its GND pole.
4 wires would be a bit artificial for that project, 3 wires is sufficient.
The design is a bit counterintuitive as quadratic nonlinearity is compensated by linear (with offset) correction of the gain.
I agree : over-engineered (in calculations, still simple design - a controversy),
shows something obsolete as nowaday thermocouples and Pt100 amplifiers/conditioners in-one ICs offer amplification and linearisation,
some ICs add ADC with SPI interface in one chip.
Fully analog ICs make it using similar but a bit better compensation of Pt100 non-linearity.
ICs with digital part inside don't care for non-linearity (compensated in analog way), the relevant linearisation is a part of inside software, a linearisation table.
Anyway - a piece of good training and ... history. And very simple design, which may make it usefull (quick to be made)
@@marekrawluk Well said! Thank you for your interest in this circuit and for sharing your thoughts and insights. You have a good point about the learning aspect of these circuits. In line with that, here is one unique example of the application of PTC TempCo resistors to realize an Analog Power Raiser computer Circuit ua-cam.com/video/Qe3cY9JSzYg/v-deo.html . I hope you also find it interesting,
PT100 RTD Temperature detector circuit with Error Compensation is explained in this video. For more sensor amplifiers see ua-cam.com/play/PLrwXF7N522y7Ut9bm8TXAOhIWqL__FGlj.html and the following videos: Thermocouple Amplifier with Cold Junction Compensation ua-cam.com/video/-BsDLBI166U/v-deo.html
Thermometer Sensor Circuit Explained ua-cam.com/video/5jmbZ9ak6EI/v-deo.html
Strain Gauge Wheatstone Bridge Instrumentation Amplifier Explained ua-cam.com/video/io1yBcCsP-Y/v-deo.html
PhotoDiode Amplifier with Data Compression Explained ua-cam.com/video/hqrRx2ufAwg/v-deo.html
Thermometer Circuit Design with Op Amp and BJT transistor ua-cam.com/video/55YsraFE0rg/v-deo.html
Thermometer Current source ua-cam.com/video/Ggf0yCaTTiY/v-deo.html
Digital Stethoscope Microphone Amplifier Explained ua-cam.com/video/ez5KtkPbsHg/v-deo.html
Temperature-Compensated Programmable Current Source Circuit Design with Zener Diode, BJT Transistors ua-cam.com/video/QY48IQXJIRI/v-deo.html
Temperature-Independent Current Circuit Design with Op Amp, BJT, Zener, Schottky Diodes ua-cam.com/video/hFbnjbddUvs/v-deo.html
Instrumentation Amplifier with Electronic Gain Control ua-cam.com/video/C4tghZ-q6Zs/v-deo.html
For more analog circuits and signal processing examples see: ua-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html
I hope these sensors circuits videos are interesting and useful.