Teledyne API - Model 200EH/EM Operation Manual Optional Hardware and Software
45
EXHAUST MANIFOLD
VACUUM
PRESSURE
SENSOR
SAMPLE
PRESSURE
SENSOR
O3 FLOW
SENSOR
FLOW PRESSURE
SENSOR PCA
INSTRUMENT CHASSIS
PMT
PERMAPURE
DRYER
NO/NOX
VALVE
AUTOZERO
VALVE
O3
Scrubber
O3
GENERATOR
O3
Purifier
EXHAUST
GAS
OUTLET
Filter
NO2
Converter
BYPASS
MANIFOLD
REACTION
CELL
Orifice Dia.
0.003"
Orifice Dia.
0.007"
Orifice Dia.
0.004"
GAS INPUT
MANIFOLD
ZERO AIR
INLET
Zero Gas
Valve
Low Span
Valve
High Span
Valve
Span/Cal
Valve
SAMPLE
GAS
INLET
LOW
SPAN AIR
INLET
HIGH
SPAN AIR
INLET
PUMP
NOX Exhaust
Scrubber
Figure 5-6: M200EM – Internal Pneumatics with Second Span Point Valve Option 52
5.8. OXYGEN SENSOR (OPT 65)
5.8.1. THEORY OF OPERATION
5.8.1.1. Paramagnetic measurement of O2
The oxygen sensor used in the M200EH/EM analyzer utilizes the fact that oxygen is attracted into strong
magnetic field, most other gases are not, to obtain fast, accurate oxygen measurements.
The sensor’s core is made up of two nitrogen filled glass spheres, which are mounted on a rotating suspension
within a magnetic field (Figure 5-7). A mirror is mounted centrally on the suspension and light is shone onto the
mirror that reflects the light onto a pair of photocells. The signal generated by the photocells is passed to a
feedback loop, which outputs a current to a wire winding (in effect, a small DC electric motor) mounted on the
suspended mirror.
04521C (DCN5731)