Technical data
Table Of Contents
- Contents
- Introduction
- System Description
- Installation
- Overview
- Step 1: Selecting a Location
- Step 2: Unpack and Inspect the Instrument
- Step 3: Set Up the Vacuum Pump
- Step 4: Connect the Power Cord
- Step 5: Install the Dry Compressed Air or O2 Supply
- Step 6: Install the Signal Output Cables
- Step 7: Install the Dual Plasma Burner
- Step 8: Install the Dual Plasma Controller
- Step 9: Install Column Connections
- Step 10: Install the Transfer Line
- Front Panel Controls and Initial Startup
- Operation
- Maintenance
- Pump Maintenance
- Cleaning the Detector
- Changing the Oil Mist Filter (RV5)
- Reaction Cell Cleaning
- Flow Sensor Calibration
- Detector Sensitivity
- Assembling the Dual Plasma Burner for Component Replacement with the SCD
- Assembling the Dual Plasma Burner for Component Replacement with the NCD
- Tube Replacement for the SCD
- Tube Replacement for the NCD
- Troubleshooting
- Index
34 Operation and Maintenance Manual
directly in front of the photomultiplier tube (PMT). A red cut-off filter between
the reaction cell and the PMT selectivity transmits the light from the nitric
oxide and ozone reaction.
Efficient combustion in the ceramic tubes and the red cut-off filter eliminate
interference from non-nitrogen containing analytes (sulfur dioxide, alkenes,
olefins) that have chemiluminescence reactions with ozone.
A background signal is typically present as a result of ozone-wall interactions
and low level nitrogen contamination from carrier and detector gases. The
background signal is a useful troubleshooting aid.
NCD Photomultiplier Tube and Cooler
In the NCD, a red-sensitive PMT detects emissions from the nitric oxide and
ozone reaction. A thermoelectric cooler cools the PMT 40 °C below ambient
temperature to approximately -15 to -20 °C to reduce background noise from
the PMT. The cooler operates whenever the Detector is connected to AC power.