At Powers Scientific, we offer several different types of temperature controlled chambers with additive humidity, such as humidified incubators for ninhydrin testing and shelf life testing, plant tissue culture chambers, drosophila/mosquito and small insect chambers, and pharmaceutical or cosmeceutical/nutriceutical temperature and RH stability chambers. In order to produce the required relative humidity for each application, we use three different types of humidity generators.
The most basic type of humidity generator is our heated pan. This generator is a small trough that sits inside the chamber (usually mounted on one of the side walls). Plumbed water is fed into the trough where a heating element turns the water into steam to generate the required humidity. The upside of this design is that it is capable of generating lots of humidity and is inexpensive to replace. The downside is that an open trough of water is always present and it uses more power than the other two types. Distilled or reverse osmosis (RO) water is the recommended water source for the best system performance (unless drosophila are being raised in the chamber – then, tap water is recommended).
A more sophisticated type of humidity generator is our HUMGEN hot-target humidity generator. This device has a nozzle that sprays water at a heating element, which vaporizes the water to generate humidity. It is very responsive and accurate, capable of generating precise amounts of humidity quickly. However, the system does require ultrapure de-ionized (16-18 megohms resistivity) water to function properly. Of course, we also offer an ultrapure DI water capture and re-circulation system to provide a “green” way to deliver the correct water quality at the correct incoming pressure. These humidity generators are always used in stability chambers.
Our newest type of humidity generator is the ULTRAGEN, an ultrasonic humidity generator that fits easily into your palm. Ultrasonic generators work by creating high-frequency oscillations in the water. When the water tries to follow the high-frequency vibration, the pressure created by the rapid movement causes water molecules to be ejected from the surface of the water in a fine mist. Unlike the other two units, which require the use of specialized water sources, regular tap water may be used in the ULTRAGEN unit. This unit is perfectly suited for applications at higher than ambient room temp set points, since it doesn’t produce copious amounts of humidity in the presence of refrigeration. Ninhydrin testing and drosophila rearing applications are examples of where this system shines.
For more information on our humidified chambers, please see our product pages, request a catalog, or call us at (800) 998-0500.