RD4: 250-280-RI-Cond

UV, RI and Conductivity Monitor for Preparative liquid chromatography and FPLC

GeneralSpecificationsOptionsSeparation ExamplesFraction RouterUser Manual


The RD4 detectors are tailored to chromatographic separations of samples between 2mg and 200g per typical run. They are equally compatible with aqueous and organic solvents, and are ideal for both Chemistry and Life Science research.

Due to exceptionally wide absorption range of 0.001 to 100 AU (US patent) the data is never off scale, allowing non-blind collection of desired fractions even at the highest solute concentrations.

The RD4 can also be used as an semi-industrial process controller that reacts to detected effluent composition.

REACH Devices instruments are problem-free, user-friendly, long-lasting and exceptionally small. They serve for years with minimum maintenance requirements, with no need to purchase new lamps, flow cells, software, etc.

RD4-250-280-RI 4-channel preparative flash chromatography detector
Acquizition Screen of RD4-250-280-RI preparative liquid chromatography detector front view of RD4-250-280-RI preparative liquid chromatography detector bottom view of RD4-250-280-RI preparative liquid chromatography detector back view of RD4-250-280-RI preparative liquid chromatography detector Glass column adapter

An optional Fraction Router with up to 16 solenoid valves can be added to all RD4 detectors. The router allows to automatically collect fractions of unlimited volume into user-supplied vessels. The collection criteria are based on signal thresholds (UV absorption, pH, conductivity or RI), time windows, or a combination of both.


  • The detector features three simultaneous data acquisition techniques in a single embedded flow cell:
    • Fixed length UV absorption monitoring at 250 and 280 nm
    • Refractive index monitoring at 280 nm
    • Conductivity or Proton Mobility monitoring (see specifications page for details)
  • UV LED light sources provide over a decade of consistent function while eliminating warm-up time.
  • UV light intensity is temperature-independent to minimize long-term drift.
  • Flow rates from 0.1 to 300 ml/min.
  • Pressure limit is 2500 psi (170 bar).
  • The flow cell is compatible with any common solvent except HF.
  • The flow cell total volume is 0.25 ml.
  • The chromatogram is graphed in real time on an embedded 5.7-inch LCD.
  • Data is recorded to an internal, non-volatile (non-powered) memory, and can be transferred to a USB drive in a simple format exportable to software of your choice.
  • The detector is compatible with virtually any fraction collector.
  • Included universal column adapter makes attaching the RD4 to any column or cartridge effortless – glass, FPLC, HPLC.
  • Durable anodized titanium case and shielded display provide near-total solvent-resistance.
  • Works with both 120V and 220V line voltage, 10W max power draw,power interruption resistant.
  • Three years warranty. List price $5143.00. To order contact sales@reachdevices.com for a quote.

Superior performance that outclasses all comparable instruments

The comparison chart of commercially available UV detectors and monitors for liquid chromatography

How to Choose a UV Detector for Chromatography Applications