Teledyne 100AH instruction manual Sample Flow

Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D

Sample Flow

The sample flow is computed from the pressure measured upstream of the flow control module. Since the downstream of the orifice is well within the critical pressure (which is also checked continuously), it is the upstream pressure of the orifice responsible directly proportional to the flow through the orifice. Flow variation has little effect on the analyzer reading. Its nominal value is 650 ± 60 cc/min.

PMT Voltage

The PMT VOLTAGE measures the PMT signal at the output of the preamp board. The waveform of the PMT voltage can be complex, and vary up to 5000 mV when a high concentration of SO2 is being measured. If the PMT reading is consistently 5000 mV, that indicates an off-scale reading. Typical readings bounce around, which is normal.

UV Lamp

UV Lamp reading is the measurement voltage from the reference detector preamp board. Typical value is between 2000 mV and 4000 mV and above 600 mV is acceptable.

Stray Light

Stray Light is the background light of the reaction cell expressed in PPM while sampling zero gas. It is only an indication of the condition of the optical system such as lenses, UV filter, light leak, etc.

Dark PMT

The dark current of the PMT is periodically measured to compensate any PMT dark current drift and offset. Typical value is less than 200 mV.

Dark Lamp

This is the dark current of the UV reference detector which is used to compensate any dark current drift and offset. This measurement is synchronized to the Dark PMT measurement period. Typical value is less than 200 mV.

Slope

The coefficient of straight line equation (y = mx + b) determines the calibration of the M100AH. The slope parameter (m) can be thought of as a gain term which determines the steepness of the calibration curve. Typical value is 1 ± 0.3.

Offset

The offset parameter (b) compensates for differences in the background signal of the optical system. Typical value is less than 100 mV.

5-8