Oxygen Analyzer | Operational Theory | |
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as the signal is passed to a second channel of the analog to digital converter.
The raw counts of the analog to digital converter for both the oxygen sensor amplifier and temperature amplifier are sent to the PPC via RS232 interface once every second along with a status byte. The PPC performs processing on this data to calculate oxygen concentration, temperature, as well as decisions regarding the condition of the alarm contacts, range, amplifier gain, solenoid control, and the analog output required. After processing, the PPC sends a message back to I/O board, via RS232, with commands for all the I/O functions. The 8051 microprocessor in the I/O board evaluates this data and the appropriate control signals are directed to the LED display, alarms contacts, range ID contacts, and digital to analog converter. The analog to digital converter is a 12 bit device located in the microprocessor IC. The output of the digital to analog converter with the help of some support electronics produces the
Signals from the power supply are also monitored, and through the microprocessor, the system failure alarm is activated if a malfunction is detected. Failure to communicate with the PPC will also trigger the System alarm.
Teledyne Analytical Instruments | 27 |