Operating instructions for Grumbach Incubators - Lyon

Humidity Control
On incubators where the auto-Humidity feature is not fitted the humidity can be increased via filling the bottom
tray with water. As relative humidity is directly proportional to the surface area of water, small receptacles may
be placed on the floor of the incubator with different surface areas until the desired humidity level is obtained.
On auto-humidity incubators the reservoir should be filled using distilled water to combat lime scale build up
within the reservoir. Opening or closing the Humidity flap to various degrees can alter the humidity level to
suit most incubation needs. If when the flap is fully open (white line is at three o’clock) the humidity is still not
as high as you require then switch on the Humidity on/off switch. By turning the Humidity up/down switch this
will increase the humidity level up to 100%.. Once the on/ off switch is turned on there is a small heater
situated under the water reservoir, which warms the water, and so assists in evaporation hence increasing the
humidity level. The up/down switch is a simple thermostat that allows you control over how warm the water
gets. By using this facility in conjunction with the flap, you can control the humidity level to your exact
requirements
Make sure the water level is topped up this is easily viewed through the plastic filling tube. Whenever the
incubator is not in use or is being moved, empty any water from the reservoir into a bowl by removing the
drain plug at the base of the filling tube and tilt the incubator forward slightly.
To calibrate the dial humidity gauge, wrap it up in a damp cloth for 15 minutes. Then with a small screwdriver
turn the pointer via the screw in the back off the gauge to 100%. Then leave for it to drop to ambient humidity
level (generally between 30-50 %).
To calibrate the digital Hygrometer remove the front the same as the digital thermometer. The two calibration
screws are found on the side of each digital digit.
Calibration Screws
Fig 7. Dial Hygrometer
Fig 8. Digital Hygrometer Calibration