Teledyne 6200E - Sulfides Analyzer - Manual (Page 226)

Theory Of Operation Model 6200E Instruction Manual
226 M6200E Rev: A1
10.4.7. Pneumatic Sensor Board
The flow and pressure sensors of the M6200E are located on a printed circuit assembly just behind
the PMT sensor. Refer to Section 11.5.15 on how to test this assembly. The signals of this board
are supplied to the motherboard for further signal processing. All sensors are linearized in the
firmware and can be span calibrated from the front panel. See section 6.9.8 for instructions on
performing this test.
10.4.8. Relay Board
The relay board is the central switching unit of the analyzer. It contains power relays, status LEDs
for all heated zones and valves as well as valve drivers, thermocouple amplifiers, power
distribution connectors and the two switching power supplies of the analyzer. The relay board
communicates with the motherboard over the I
2 C bus and is the main board for trouble-shooting
power problems of any kind.
10.4.8.1. Heater Control
The M6200E uses a variety of heaters for its individual components. All heaters are AC powered
and can be configured for 100/120 VAC or 220/230VAC at 50-60 Hz.
The two sample chamber heaters are electronically connected in parallel for analyzers at 100/120
VAC line power and in series for units configured for 220/230 VAC. One configuration plug on the
relay board determines the power configuration for the entire analyzer.
On units with IZS options installed, an additional set of AC heaters is attached to the IZS
permeation tube. Some special M6200E models may have other, non-standard heating zones
installed, such as a dilution manifold.
In order to operate efficiently, the H
2
S Æ SO
2
converter must be heated to 315˚C. An AC band
heater wrapped around the converter cartridge contains two heater coils that are also configured
in parallel or in series depending on the Type of AC power being supplied. A thermocouple
imbedded in the heater measures the temperature and feeds a small voltage to the relay board’s
thermocouple amplifier, which, in turn, transmits the linearized analog voltage to the
motherboard. This information is sent to the CPU via the instruments
I 2 C buss. The CPU returns
activate/deactivate signals to the appropriate relay also via the I 2 C buss.
On units with IZS options installed, an additional set of AC heaters is attached to the IZS oven.
Some special M6200E models may have other, non-standard heating zones installed, such as a
bypass manifold.
10.4.8.2. Valve Control
The relay board also hosts two valve driver chips, each of which can drive up four valves. In its
basic configuration the Model 6200E requires no special valves to operate. However, on units with
either the zero/span valve or the IZS option installed The valves are. Manifold valves may also be
present in certain special versions of the analyzer.