Shellab SHC28R-2 - Manual (Page 9)

9
OPERATION
It is recommended that your unit be allowed to reach operating temperature before engaging the humidifying
system. This requires setting the RH set point to 0 (zero) until the unit is at operating temperature. See
Section 6.6 for changing the RH set point.
6.1 Turn the power switch to the I/ON position. Turn the High Limit Safety thermostat to its maximum
position, clockwise and place the shelves in the chamber.
6.2 Place a reference thermometer in the chamber where it can be easily viewed, and so that it is not
touching any shelves or chamber walls. Taping the thermometer to a petri dish is a method that works
well.
6.3 Set Main Temperature Control: To enter the set point on the control, push and release either the UP
or DOWN arrow pad one time and the digital display will start to blink from bright to dim. While
blinking, the display is showing the set point, which can be changed to the desired temperature by
pushing the UP or DOWN arrow pads. If the arrow pads are not pushed within five (5) seconds, the
display will stop blinking and will read the temperature in the chamber. Allow at least twenty- four (24)
hours for the temperature to stabilize. It is recommended that set point adjustments are made again
after the calibration procedure is completed.
6.4 Calibrating Temperature Control: Compare the reading on the reference thermometer with the
digital display. If there is an unacceptable difference, put the display into calibrate mode by pressing
both the UP and DOWN arrow pads at the same time and holding them in until the two outside
decimal points start to flash. When the decimal points are flashing, the display can be calibrated to
match the reference thermometer by pressing the UP or DOWN arrow pad until the display reads the
correct value. Allow the unit to stabilize again until five (5) consecutive readings at five (5) minute
intervals read a constant value.
6.5 Set the High Limit Safety Thermostat: After the Main Temperature Control is set and calibrated the
High Limit needs to be set. First turn the control knob counterclockwise just until the Safety Indicator
light comes on. Then slowly turn the knob clockwise just until the Safety Indicator light goes off. The
Safety thermostat should now be set approximately ten (10) degrees above the Main Temperature
Control set point.
6.6 Set Humidity Control: First, place a reference hygrometer in the chamber where it can be easily
viewed. To enter set point mode on the Humidity Control push and release either the UP or DOWN
arrow pad and the digital display will start to blink from bright to dim. While blinking, the display is
showing the set point which can be changed using the UP or DOWN arrow pads. If the arrow pads
are not pressed within five (5) seconds, the display will revert to showing the process or actual
parameter within the chamber. Allow at least twenty four (24) hours for the unit to stabilize.
CAUTION: When opening the door there is a danger from the steam/high humidity escaping.
The door should be opened a small amount (2" - 3") then paused until the steam cloud
dissipates.
6.7 Calibrating Humidity Control: Compare the reading on the reference hygrometer with the digital
display. If there is an unacceptable difference, put the display into calibrate mode by pressing both the
UP and DOWN arrow pads at the same time until the display begins to blink. When the display is
blinking it can be calibrated to match the reference hygrometer by using the Up/Down arrow pads until
it reads the correct value. If the arrow pads are not pressed within five (5) seconds, the display will
revert to showing the process or actual parameter within the chamber. Allow the unit to stabilize
again.
Section
6