Agilent G7162-69001 is an original service optical unit assembly designed for the Agilent 1260 Infinity II Refractive Index Detector (RID), model G7162A. The optical unit forms the central measurement section of the detector and incorporates the optical and fluidic path required to measure refractive-index differences between the reference and sample cells.
Optical Unit Function
The Optical Unit Assembly is the central measurement component of the refractive index detector.
During operation, column effluent passes through:
- the heat exchanger,
- the sample cell,
- and then into the detector valve system.
The reference cell contains mobile phase and provides the reference optical path.
When the refractive index of the liquid in the sample cell changes, the light beam is deflected and falls unevenly on the two photodiodes. The resulting differential signal is converted into the detector response in RIU.
Optical Path Components
The standard G7162A optical unit incorporates components including:
- light source,
- condenser lens,
- collimator lens,
- sample cell,
- reference cell,
- zero glass,
- mirror,
- photodiodes,
- heat exchanger,
- heater,
- associated internal capillaries.
Temperature Stabilization
Refractive-index measurements are highly sensitive to temperature changes.
The optical unit therefore provides active temperature control over approximately:
- 5 °C above ambient to 55 °C
The heat exchanger and controlled optical-unit temperature help minimize baseline drift caused by temperature fluctuations in the mobile phase.
Flow Cell
For the standard G7162A optical unit:
- Sample cell volume: 8 µL
- Maximum pressure: 5 bar
- Maximum flow rate: 5 mL/min
- Inlet port to sample cell: 62 µL
- Inlet port to outlet port: 590 µL
Wetted Materials
The standard G7162A RID flow path uses:
- 316 stainless steel
- PTFE
- quartz glass
Supported pH range: 2.3–9.5
Technical Specifications
- PN: G7162-69001
- Compatible Module: G7162A RID
- Technique: LC
- Detection: Refractive Index
- Optical Unit Type: Standard
- Sample Cell Volume: 8 µL
- Maximum Cell Pressure: 5 bar / 0.5 MPa
- Maximum Flow Rate: 5 mL/min
- Inlet-to-Sample-Cell Volume: 62 µL
- Inlet-to-Outlet Volume: 590 µL
- Liquid Contact Materials: 316 SS, PTFE, quartz glass
- pH Range: 2.3–9.5
- Optics Temperature Control: ambient +5 °C to 55 °C
