Instruction manual

SM425 INSTRUCTION MANUAL 10.0 OTHER FUNCTIONS
156 42500001 REV A
10.1.1.7
10.1.1.8
10.1.1.9
10.1.1.10
10.1.1.11
10.1.1.12
10.1.1.13
10.1.1.14
10.1.1.15
Thermocouple Voltage
The cell temperature is measured with a Type K (chromel-alumel) thermocouple. The thermocouple cold
junction is located in the detector terminal box. The cell temperature and the thermocouple voltage
(including the voltage corresponding to the cold junction temperature) are displayed.
Cold Junction Resistance (C.J. Voltage)
The SM425P Detector measures the cold junction temperature using an RTD (Pt 1000). The RTD
resistance is displayed as the cold junction resistance.
Cell’s Internal Resistance
A new cell (sensor) indicates an internal resistance of 200Ω maximum. As the cell ages, the cell’s internal
resistance will increase.
Software Revision
The revision (number) of the software installed is displayed.
Maximum Oxygen Concentration
The maximum oxygen concentration and the time of its occurrence during the period specified in the
Averaging display are displayed. If the setup period elapses, the maximum oxygen concentration that has
been displayed so far will be cleared and a new maximum oxygen concentration will be displayed. If the
setup period of time is changed, the current maximum oxygen concentration will be displayed (for more
details, see Section 1.50.2 earlier in this manual).
Minimum Oxygen Concentration
The minimum oxygen concentration and the time of its occurrence during the period specified in the
Averaging display are displayed. If the setup period elapses, the minimum oxygen concentration that has
been displayed so far will be cleared and a new minimum oxygen concentration will be displayed. If the
setup period of time is changed, the current minimum oxygen concentration will be displayed (for more
details, see Section 1.50.2 earlier in this manual).
Average Oxygen Concentration
The average oxygen concentration during the periods over which average values are calculated is
displayed. If the setup period elapses, the average oxygen concentration that has been displayed so far
will be cleared and a new average oxygen concentration will be displayed. If the setup period of time is
changed, the current average oxygen concentration will be displayed (for more details, see Section 1.50.2
earlier in this manual).
Heater On-Time Ratio
The probe sensor is heated to and maintained at 750°C. When the measured gas temperature is higher
than 750°C, the heater ON-time will decrease.
Time
The current date and time are displayed. These are backed up with built-in batteries. No adjustment is
required after the power is switched off.