Temperature Measurement Sequence; Mpx Data; Temperature Calculation Formula; Incubator Temperature (Pt Feeler) - Hitachi 902 Service Manual

Temperature Measurement Sequence

Dummy lead
Reference
Lead/
2 V
incubator
changeover
changeover
AD START AD START
Cycle 1
• Calculation/alarm judgement are made in the past three cycles.
The temperature is judged according to the status and an alarm is output.
The temperature used for judgement is calculated in the following manner.
1. Average of 4 temperature values measured in a single cycle
2. Average temperature in 3 cycles
3. Alarm judgement by value rounded to 1st decimal point and multiplied by 10
(1)

MPX Data

No.
1 Reference voltage (2 V)
2 Incubator temeprature
3 Reference voltage (6 V)
(2)

Temperature Calculation Formula

1)

Incubator Temperature (Pt feeler)

T = 29.0 × (Y - A)/(B - A) + 7.96
T: Incubator temperature (° C)
Y: ADC count value at measurement
A: Count value for reference voltage (2 V)
B: Count value for reference voltage (6 V)
NOTE: The interrupt register is 100 msec before A/D start.
Dummy lead Dummy lead
Lead/
Lead/
incubator
incubator
changeover
changeover
AD START
AD START
3 cycles (54000)
Cycle 2
Item MPX Data
Dummy lead
Dummy lead
Lead/
Lead/
incubator
incubator
changeover
changeover
AD START
AD START
Temperature ADC
400 msec × 6 cycles : 2.4 sec
Cycle 3
6
5
7
7 - 18
Dummy lead
Lead
: Required time