Teledyne 6200E - Sulfides Analyzer - Manual (Page 229)

Model 6200E Instruction Manual Theory Of Operation
M6200E Rev: A1 229
PMT TEMPERATURE: This signal is the output of the thermistor attached to the PMT cold block
amplified by the PMT temperature feedback circuit on the PMT preamp board. It is digitized and
sent to the CPU where it is used to calculate the current temperature of the PMT.
This measurement is stored in the analyzer’s memory as the test function PMT TEMP and is
viewable as a test function (Section 6.2.1) through the analyzer’s front panel.
SAMPLE GAS PRESSURE SENSOR: This sensor measures the gas pressure at the exit of the
sample chamber.
SAMPLE FLOW SENSOR: This sensor measure the flow rate of the sample gas as it exits the
sample chamber.
10.4.10.3. Thermistor Interface
This circuit provides excitation, termination and signal selection for several negative-coefficient,
thermistor temperature sensors located inside the analyzer. They are:
SAMPLE CHAMBER TEMPERATURE SENSOR: The source of this signal is a thermistor embedded in
the of the sample chamber block. It measures the temperature of the sample gas in the chamber.
This data are used by the CPU to control sample chamber the heating circuit and as part of the
H
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S, calculations when the instrument’s Temperature/Pressure Compensation feature is enabled.
This measurement is stored in the analyzer memory as a parameter (RCEL TEMP) and is
viewable as a test function under the same name (Section6.2.1) through the analyzer’s front
panel.
IZS OPTION PERMEATION TUBE TEMPERATURE SENSOR: This thermistor, attached to the
permeation tube in the IZS option, reports the current temperature of that tube to the CPU as
part of control loop that keeps the tube at a constant temperature.
BOX TEMPERATURE SENSOR: A thermistor is attached to the motherboard. It measures the
analyzer’s inside temperature. This information is stored by the CPU and can be viewed by the
user for troubleshooting purposes through the front panel display. This measurement is stored in
the analyzer. Memory as the test function BOX TEMP and is viewable as a test function (Section
6.2.1) through the analyzer’s front panel.
10.4.11. Analog Outputs
The analyzer comes equipped with four Analog Outputs: A1, A2, A4 and a fourth that is a spare.
A1 and A2 Outputs: The first two, A1 and A2 are normally set up to operate in parallel so that
the same data can be sent to two different recording devices. While the names imply that one
should be used for sending data to a chart recorder and the other for interfacing with a
datalogger, either can be used for both applications.
Both of these channels output a signal that is proportional to the O
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concentration of the sample
gas. The A1 and A2 outputs can be slaved together or set up to operated independently. A
variety of scaling factors are available, See Section 6.7 for information on setting the reporting
range type and scaling factors for these output channels
Test Output: The third analog output, labeled A4 is special. It can be set by the user (see Section
6.9.10) to carry the current signal level of any one of the parameters accessible through the TEST
menu of the unit’s software.