Smokehouse analogue thermometer for PT1000, LM358 and ESP8266

Hi,
i am creating a thermometer for the smokehouse ... .
I have managed to make an analogue temperature sensor based on a PT1000 sensor at this point. It comes in a gel cable. According to the manufacturer the range can be -50*C-200*C. I managed to get max. 144*C. I don't know if the LM358 limits this ?
The PT1000 sensor is supposed to measure the smoke temperature.

The circuit is based on an ESP8266 Wemos. It is accompanied by an LCD1602 display. I'm running on ESP Easy and I'm fine with it.
I may do a second option with zaSUPLOwing - Supla has a good readable app on the tel.
I calibrated the sensor at two points : at 100*C and 0*C. I also fitted a second sensor : DS18B20, but this one will be as an outdoor temp, or a sensor to stick in the meat.

I would still like to do e.g. a fiddly thing like some sort of buzzer when the temperature rises, or falls below the range, to either boost or dim.

https://www.onsemi.com/pdf/datasheet/lm358-d.pdf
pp. 4 - output voltage high limit

That's what I suspected, in the kk LM358 it says up to 150*C -mi up to 144*C, but more than that I'm unlikely to need, but it begs the question what layout for higher temperatures?

Added after 3 [minutes]:

I sealed the whole thing in tins.

Reduce R4 to 5 kΩ and scale the transmitter in the software.

OOO , thanks - I will be happy to test .

Added after 11 [hours] 7 [minutes]:

Works, thanks to
Increased the temperature measurement range on the PT1000 after changing resistor R4 to 5kOhm. Of course I recalibrated it as well.

Haven't you thought about something like this https://www.gotronik.pl/modul-wzmacniacza-do-...00-pt1000-spi-max31865-konwerter-p-11821.html ?

>>21750183
OO Lord you see-that's another good idea. Thanks.
https://espeasy.readthedocs.io/en/latest/Plugin/P039.html
The library I can see would be, there is a description of what and how.
For the smokehouse I don't need such accuracy, butee I was planning to make precise temperature sensors for the heat meter I have for the heat pump- there two decimal places would be useful because now I have for it on DS18B20 and it's Chinese, so .... accuracy of measurement and calculation, indications - poor.

sznickers wrote:

Hi,
i am creating a thermometer for the smokehouse ... .
I have managed to make an analogue temperature sensor based on a PT1000 sensor for the moment.

And not simpler to use a budget specialised RTD Adafruit MAX31865. 10zl at a Chinese manufacturer. Measurement with an accuracy of 0.2*C. Plenty of code examples on the web.

>>21750456
Well that's what I understand tos18 wrote about

I wouldn't be writing if I hadn't tested it and I'm very satisfied. https://www.elektroda.pl/rtvforum/topic4152238.html

>>21750717
Very cool design.

I have now added the video

sznickers wrote:

For the smokehouse I do not need such accuracy, but I was planning to make precise temperature sensors for the heat meter I have for the heat pump- there two decimal places would be useful because now I have on it on DS18B20 and it is Chinese, so .... accuracy of measurement and calculation, indications - poor.

It says: The module provides a high measurement accuracy of 0.5°C
This is what the DS18B20 will also achieve. Plus the non-linearity of the PT. And the heat meter is not so simple, because you still have to measure flows.

krzbor wrote:

because you still have to measure the flows.

i know-I have no problem with this .
Professional heat meters are based on PT temperature sensors , but certainly not DSs. Basically with LC it is the delta that is important, or in other words both sensors next to each other at the same temperature you need them to indicate the same thing.
Coming back to the DS18B20 - it would be interesting to see how the original ones would behave.
However, here in my project I use a PT1000 sensor because the DS ends its operating range at 125*C.

sznickers wrote:

Back to the DS18B20-I wonder how the original .

would behave
According to the data sheet, that is, a maximum error of 0.5 degrees (probably less), and a resolution (12 bit) of 0.0625 degrees. Once these have been calibrated, the difference between the two can be determined and corrected by software. By the way - write what results you got from the Chinese and why are you complaining so much about them? I've encountered mishandling of the standard - i.e. they don't always work on two wires, but when there is a separate power supply (3 wire connection) it's OK.
And this is a review from Allegro (waterproof sensor with wire for £6):
Although according to the serial number it is not an original Dallas the indications are very precise. Out of the 4 pieces purchased, only one indicated a difference of 0.2*C from the others. This is very little! and comparing with a laboratory thermometer, these 3 indicated 0.1*C more and this one 0.1*C less.

Kamstrup has PT500 sensors.

How accurately do these temperature sensors indicate-precision to 0.01*C !

As for the DS180B20- what people write there, let them write- I always connect 3-wire with 12bit resolution. What DS I will show another time a test-their comparison.

Added after 2 [minutes]:

sznickers wrote:

How accurately do these temperature sensors indicate-precision to 0.01*C !

Don't confuse resolution with measurement accuracy, buddy !

>>21751691
I know what you are writing about.
I connected the two sensors together during a real-time measurement.

Added after 2 [hours] 33 [minutes]:

Above 128*C the DS18B20 shuts down, fades out, below that temperature it comes back, and the PT1000 bravely works.
The 7 segment display maybe like a senior citizen, but in practice the best.

Preview in Domoticz :

34*C is the meat temp, (DS18B20) and 65*C is the PT1000 analogue .
I fitted two lights, LEDs to indicate when the temperature is exceeded (dim) , or is too low (sub) or yellow - when the meat reaches 70*C.

Comparison of 4 ds18b20 sensors - two each on the supply and two on the return, preview while the heat pump is on:

Viewed while the heat source is off. and while the circulation pump is on - so theoretically they should all be equal:

Conclusion: I could apply a sensor correction, a little will only help.

Added after 7 [minutes]:

Meat smoking chart:
Meat temperature from 20*-55* for a smoking time of approx. 8h

Smoke temperature: