Hi, Perminder!

I have no personal experience using potassium hydroxide, but here is a list of a few other salts and their relative humidity levels.

regards,

Daniel

http://www.omega.com/temperature/z/pdf/z103.pdf

Hi, I also have no personal experience about the controlling humidity in closed grain storage chamber. But I can suggest you to use humidity sensors.

Dear Dr. islam, we have humidity chamber. Because of temperature maintained inside the chamber (Around 30 - 40 degree), it is expected that some moisture will be lost from grain. So we want to use KOH/NaOH solution to maintain humidity in the closed container storing grain. i wanted to know about exact procedure for the same.

I do an experiment saturated salt solutions. The saturated KCl solution able to control a closed relatuva 82% of humidity. I prepare a saline solution saturated with KCL 250 g and 250 ml of H2O in a container Volume 5 L. Let the solution stand for 7 days with us humidity sensor inside the container.

Is there any reference available for the same?

Right now I'm doing studies with other saline solutions for absorption curves of wettable powders but with 150 g NaOH and 250 ml of H2O I have obtained a relative humidity of 42%

Estas son algunas de las referencias que sobre el tema

AYALA APONTE, A., SERNA COCK, L., & RODRIGUEZ DE LA PAVA, G. (December de 2011). MOISTURE ADSORPTION ISOTHERMS IN YELLOW PITAHAYA (Selenicereusmegalanthus). Dyna(170), 7-14.

Labuza, T. A. (1985). Effect of temperature on the moisture sorption isotherm and water activity shift of two dehydrated food. Journal Food Science, 50, 392-396.

Pita Díaz, D., & Rojas Wittkera, O. (2001). DETERMINACIÓN DEL CONTENIDO DE HUMEDAD DE EQUILIBRIO DEL PSEUDOTALLO DEL PLÁTANO. TECNOLOGÍA QUÍMICA, XXI(1).

Dear Perminder,

here is a link to a more or less complete list of common salts that yield a specific relative humidity, ranging from 3 to 75 % (at 25 degress C), including potassium hydroxide. I believe you will be able to find a suitable salt for your experiments there, regardless of temperature.

regards,

Daniel

http://nvlpubs.nist.gov/nistpubs/jres/81A/jresv81An1p89_A1b.pdf

Thank you

Perminder Hi

I see others have provided you with information about using KOH for humidity control. KOH being caustic is not very nice to work with.  However, it has one advantage in that it absorbs CO2 so your experiment is not likely to be adversely affected by CO2 accumulation.  However, you will still need to air the system to ensure that oxygen levels don't become limiting (important if you are working with insects on grain).  If you wanted to avoid using a caustic salt like KOH then could instead use glycerol, which offers a range of different humidities depending on the ratio of water to glycerol which gives different specific gravities.  You can easily check the SGs with a hydrometer.  The following the link below for more details.   

http://corrosionjournal.org/doi/abs/10.5006/0010-9312-14.3.17