Heater Control - Teledyne T200 User Manual

HEATER CONTROL

For a variety of reasons such as, efficiency of certain chemical reactions, stabilization of
sample gas temperature and pressure, etc., various subcomponents are heated/cooled.
Two types of sensors are used to gather temperature data for the CPU:
THERMISTORS: These are used in areas where the temperature control point is at
•
or near ambient temperature (e.g. the reaction cell temperature, internal chassis
temperate).
• Thermistors change resistance as they heat up and cool down. A DC signal is
sent from the Mother board of a sent voltage and current. As the thermistor
changes resistance, the returning voltage rises and falls in direct relationship to
the change in temperature.
• The output signal from the thermistors is received by the motherboard, converted
into digital data which is forwarded to the CPU.
THERMOCOUPLES: These are used where the target temperature is high.
•
• Thermocouples generate DC voltage that rises and falls as the thermocouple
heats up and cools down.
• This DC signal interpreted, conditioned and amplified by the Relay PCA then
transmitted to the motherboard where it is also converted into digital data and
forwarded to the CPU.
All of the heaters used are AC powered which are turned ON/OFF by AC relays located
on the Relay PCA in response to commands issued by the CPU.
204 Teledyne API T200 NO/NO /NO Analyzer with NumaView™ Software
2 x
083730200A DCN7962