User Manual

6 - 2
IPN 074-289L
Composer Operating Manual
6.2.1 Category 1; Temperature Related
*Temperature LED flashes rapidly when the cell’s temperature is more than 0.1 °C over
the set point and slowly flashes when the cell’s temperature is more than 0.2 °C under
the set point. Temperature may be read directly from the optional LCD instrument or
with the optional Monitor Software.
Table 6-1 Category 1; Temperature Related
Failure Symptom Visibility Effect on Accuracy
PRT ages None None, when
recommended re-zero
interval is followed
PRT opens temperature LED
extinguishes,
temperature relay opens
N/A
Heater Power "Full on"
failure
temperature LED
extinguishes,
temperature relay opens,
transducers's
over-temperature safety
switch opens (not
visible)
N/A
Temperature out of
desired set-point control
range
temperature LED
extinguishes,*
temperature relay opens
N/A
Transducer interconnect
cable opens
a) All wires
b) PRT lead(s)
c) Heater lead (s)
d) Ground
a, b & c) Same as PRT
open or temperature out
of control range
d) Noise on C signal
a, b & c) N/A
d) Noise on C signal
Temperature
measurement circuit
a) fails, or
b) gain drifts
a) temperature LED
extinguishes,
temperature relay opens
b) None
a) N/A
b) None, when
recommended re-zero
interval is followed
Transducer is located in
a place that has a
temperature higher than
the set point.
a) Rapidly blinking
temperature LED
b) Temperature relay
opens.
Proportional to
temperature
discrepancy.