The refrigeration system, defrost heater, and air circulating fan are used in
conjunction with a microprocessor controlled proportioning circuit to
achieve sensitive temperature control. An RTD (Resistance Temperature
Detector) located in the airstream senses any temperature deviation from
the control point, and heat is provided proportionally to maintain the
desired temperature. Regardless of what temperature is being maintained,
the compressor operates continuously. This constant operation alleviates
component failures associated with cycle type operation.
The circulating fan provides even air distribution throughout the chamber
and ensures temperature uniformity.
Heater On Lamp
- Illuminates when power is applied to the heater.
LED Display
- Four digits used to display the actual, set, calibrated, high
limit and low limit values.
Indicator Lamps
- There are five (5) green indicator lamps that support
the parameter showing on the display. The sixth indicator is for a high
or low temperature alarm condition. An internal audible alarm will also
sound when this alarm indicator illuminates.
Power On/Off Switch
- The Power On/Off switch provides the main
power to the incubator.
Cooling On/Off Switch
- The On/Off Cooling Switch provides better
energy and temperature performance when setting a temperature greater
than ambient (+5°C). When the setting temperature is greater than
ambient (+5°C), set the cooling switch to “Off” position.
Mute Key
- This key is used to silence the internal audible alarm and to
de-activate the external alarm device, if one is being used.
High/Low Limit Key
- This key is used to view the high or low tempera-
ture alarm setpoint. The first depression of the key selects the high
limit. The second depression selects the low limit. The respective green
indicator lamp will light.
Refrigerated Incubator
1-3
Thermo Scientific
Section 1
Installation and Start-Up
Theory of
O
peration
Explanation of Front
Panel Controls
POWER
COOLING
>AMBIENT
+
5°C
Figure 1-1.
F
ront Panel
