this is my first post and I will start with a first question.
I try to use the Inkbird ITC-100VH to control the temperature in an incubatore.
In combination with the Inkbird I use a SSR.
The heater has a power of about 60 W. The temperature sensor is a K-type.
At the beginning I started a self-tuning. Unfortunately, I do not have a graphical representation of the temperature curve. But probably you can see from the parameters that the self-tuning has determined, how sluggish and how the reaction of the controlled system is.
I set the temperature to 30 °C and the temperature in the incubator overshoots by about 2 °C.
Here are the parameters (I hope these are the most important) that the self-tuning has determined:
M50 = 71
P = 3066
t = 264
Ctl = 48
Sn = 0 (K type)
Which parameters should I change and how, so that the overshoot goes back to 0 if possible? I am aware that the time needed to reach the set point will increase.
I have tried to double or halve the parameters M50, P, t and Ctl one by one. I can’t get an idea of what I should reasonably change. Can someone please help me with this?
Please set Ctl to 0 and then execute the self-tuning function. If the temperature still fluctuates slightly, please repeat the self-tuning several times and it will tend to be accurate.
Can it work?
Thank you so much, Tania for your recommondation!
I tried it and it might be slightly better. The overschoot now is 1.2 °C. When I open the door and wait until the temperature is lowered to 28°C and close then the door again the heater starts to heat the incubator. For my feeling the heater should stop heating when the temperatur reaches 28.5 °C. Then it should wait for several minutes and if the temperature will not increase - lets say for 30 - 40 seconds then a more or less short time the heater should be powered on and so on until the setting value has been reached.
I changed the sensor type again to PT100 because the bridge (4-5) was closed.
The paramters are now:
M50 = 136
P = 5036
t = 277
Ctl = 40
Sn = 21 (PT100 type)
What do you recommend what parameter should I now adapt to come in the right direction?
An additional question: can I see whether the output is pulsing? Or turns the output LED on when the output goes lets say to 50% (less than 100%)?
Please reduce the value of Ctl setting according to the actual temperature change so that it achieves the desired effect.
For Ctl setting, please refer to section 6.10.
The output LED indicator of ITC-100VH is synchronised with the output.
Thank you again Tania!
I tried a new approach. I bought a new PT100 with a tiny sensor which has a very small mass.
I started the self-tuning and now the controller works as expected with no overshoot.
So the result is: the PT100 was too sluggish!
Maybe that other guys have the same problem. This could be one way to solve it.
Thanks for sharing