we want Help controlling oven that works with gas

this oven is uses for heating tobaco in other term we want to control the humidity at 13% inside the oven what is the best methode to control this system

 

If I understand your problem you want to control humidity by temperature. To do this you can use a standard controller and a relative humidity probe. A good control in this case could be a PI regulation, heater should be activated when relative humidity is too high.

Anyway in tabacco drying temperature and humidity are both important to get a quality product.

http://www.cet-electronics.com

 

Many moons ago before I got into controls & drives, I worked for an electronics company that specialised in environmental measurement, namely humidity. Although I believe they are no longer in this field there may be links on the web if you type in Lee Integer (Kettering, England). Please excuse my lazyness as I haven't looked myself. LI, have now become Counting Solutions Ltd - if your struggling for an off the shelf solution etc, try giving them a call, they might be able to point you in the right direction.

From memory, their humidity probes comprised of a PT100 temp sensor & a 'CCH' humidity sensor using Op-amps etc. Zero to span Calibration of these probes was performed by forcing gas through crystals into a sealed chamber obtaining upto 100% RH. I am unsure how heat from an oven would effect this (and what operational temperature the sensors are rated at). Unfortunately, I can't remember the gas or the 'crystals', however this method of calibration is obviously a method of humidity control. I'll place another post if I remember/find out more details.

In the mean time I hope I've been of some slight help & good luck.

Best regards,

Royce (UK)