Filter
Top Products
Theory Of Operation Teledyne API M100E Analyzer Operation Manual
242
The PMT temperature control loop maintains the PMT temperature around 7° C and can be viewed as test
function PMT TEMP on the front panel (refer to Section 6.2.1).
The elec
trical test (ETEST) circuit generates a constant, electronic signal intended to simulate the output of the
PMT (after conversion from current to voltage). By bypassing the detector’s actual signal, it is possible to test
most of the signal handling and conditioning circuitry on the PMT preamplifier board. Refer to Section 6.9.6 for
inst
ructions on performing this test.
The optical test (OTEST) feature causes an LED inside the PMT cold block to create a light signal that can be
measured with the PMT. If zero air is supplied to the analyzer, the entire measurement capability of the sensor
module can be tested including the PMT and the current to voltage conversion circuit on the PMT preamplifier
board. Refer to Section 6.9.5 for instructions on performing this test.
11.4.6. PNEUMATIC SENSOR BOARD
The flow and pressure sensors of the M100E are located on a printed circuit assembly just behind the PMT
sensor. Refer to Section 12.6.14 on how to test this assembly. The signals of this board a
re supplied to the
motherboard for further signal processing. All sensors are linearized in the firmware and can be span calibrated
from the front panel. Refer to Section 6.7.5 for instructions on performing this test.
11.4.7. 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.
11.4.7.1. HEATER CONTROL
The M100E 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 M100E models may have other, non-standard heating zones installed, such as a dilution manifold.
11.4.7.2. VALVE CONTROL
The relay board also hosts two valve driver chips, each of which can drive up four valves. In its basic
configuration the M100E 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.
04515F DCN6048