Thermistor Interface; Analog Outputs - Teledyne T200 User Manual

VACUUM PRESSURE SENSOR: Also located on the flow/pressure sensor PCA, this
sensor measures the pressure of the gas mixture inside the reaction cell.
O FLOW SENSOR: Located on the flow/pressure sensor PCA as well, this sensor
3
measures the flow rate of the O

THERMISTOR INTERFACE

This circuit provides excitation, termination and signal selection for several negative
coefficient, thermistor temperature sensors located inside the analyzer.
REACTION CELL TEMPERATURE (Rx Cell Temp) SENSOR: A thermistor that
measures the temperature inside the reaction cell manifold, which is used by the CPU to
control the reaction cell heating circuit and as a parameter in the temperature/pressure
compensation algorithm.
BOX TEMPERATURE (Box Temp) SENSOR: A thermistor that measures the
analyzer's inside temperature, which is then reported through the front panel display. It is
also used as part of the NO, NO
Temperature/Pressure Compensation feature is enabled (Setup>Vars>TPC Enable).
INTERNAL SPAN GAS GENERATOR (Option) OVEN TEMPERATURE: This
thermistor reports the temperature of the optional internal span gas generator's NO
permeation source to the CPU as part of a control loop that keeps the tube at a high constant
temperature (necessary to ensure that the permeation rate of NO
Note

ANALOG OUTPUTS

The analyzer comes equipped with four configurable analog outputs on the instrument's
rear panel analog connector, labeled A1, A2, A3 and A4. A variety of scaling measurement
and electronic factors apply to these signals.
OUTPUT LOOP-BACK: All of the functioning analog outputs are connected back to the
A/D converter through a Loop-back circuit. This permits the voltage outputs to be
calibrated by the CPU without need for any additional tools or fixtures.
083730200A DCN7962
gas stream as it is supplied to the reaction cell.
3
x
There are two thermistors that monitor the temperature of the PMT
assembly:
One is embedded in the cold block of the PMT's TEC. Its signal is
conditioned by the PMT preamplifier PCA and reported to the CPU
via the motherboard (see Section 6.3.3.2).
The second is located on the PMT Preamplifier PCA and is used
only as a reference for the preamplifier circuitry. Its output is
neither reported nor stored.
Teledyne API T200 NO/NO
and NO calculations when the instrument's
2
is constant).
2
/NO Analyzer with NumaView™ Software
2 x
2
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