4.3 Description Of Functional Groups - Thermo Scientific BB 150 User Manual

4.3 DESCRIPTION OF FUNCTIONAL GROUPS

Display board P001:
This is used to input and display the operating parameters, to initiate the various
routines, and to provide access to the adjustment levels.
If necessary, FL 9 can be used to adjust the display brightness.
Sensor block P002:
This is a multifunctional assembly that provides the following functions:
Sample chamber temperature measurement, Sensor PT 1000.
This is the actual lead sensor for temperature measurement and regulation.
Sample chamber temperature monitor, digital temperature sensor, type LM
75. National Semiconductor.
Sends a temperature signal via the PC bus directly to the master processor. The
signal is compared with the PT1000 value to serve as a "plausibility check" of the
measured temperatures.
If the difference between the two measured temperatures exceeds a range that
can be separately defined for the incubation and decontamination modes, the
entire system is completely shut down.
In such cases, the user can assume that the problem is either sensor drift or an
incorrect measurement. This function also represents an overtemperature
protection. Both sensors have been preadjusted to one another at the factory (the
PT1000 value is used as the reference value for the digital temperature sensor).
Sample chamber refresh, electronic commutated DC fan motor.
The air exchange rate for the fan is automatically switched between incubation
mode (low rate of 32%) and decontamination mode (high rate of 100%) by means
of pulse packet control. Control is performed directly on the sensor board by the
PIC 14000 slave μP. Supply voltage: 12 V.
CO concentration measurement, thermal conductivity detector (TCD).
2
The thermal conductivity of the sample chamber atmosphere is measured with he
aid of an NTC thermistor bridge.
Sensor-specific data storage, NVRAM.
All sensor-block-specific data are stored in the NVRAM on the sensor board. The
master processor reads/writes this information via the PC bus.
Name
Prepared
Index Name
50078923_04_CN
File
Date
JF 05.07.13
Date
Designation
Service Manual BB 150
Document No.
50 079 823
Page
5/ 5