Wyatt Technology Optilab rEX User Manual (English)

Questions and Answers:

K
Katrina EvansAug 3, 2025
What to do if my Wyatt Technology Laboratory Equipment shows a Low Light Alarm?
- C
  Christina DavisAug 3, 2025
  If your Wyatt Technology Laboratory Equipment Optilab rEX shows a Low Light Alarm, several factors could be at play. It might be due to a dramatic change in the sample refractive index, like injecting a concentrated solution directly. To fix this, ensure you're using degassed solvents to prevent air bubbles. Also, check that the LED/fiber light source is turned on. If the light source is on but the photodiode array voltage is low, a bubble in the flow cell may be the cause.
S
Samuel WilsonAug 10, 2025
Why is there a noisy baseline in my Wyatt Technology Laboratory Equipment?
- D
  denniskelleyAug 10, 2025
  If you observe an excessive baseline noise in your Wyatt Technology Laboratory Equipment Optilab rEX, start by verifying that the LED light source is on and that there is no Low Light Alarm. Disconnect the Optilab rEX from any flow system, place a plug in the OUT port, and leave the IN port open to the atmosphere. If the noise disappears, it likely originates from the chromatographic system. If the noise is intermittent during flow or persists without flow, a bubble in the flow system may be the cause. If the baseline noise continues, contact Wyatt Technology Corporation.
D
darrylduarteAug 18, 2025
How to fix temperature not setting below 20 C on Wyatt Technology Laboratory Equipment?
- J
  John MendozaAug 18, 2025
  Your Wyatt Technology Laboratory Equipment Optilab rEX might not set the temperature below 20°C if the gas pressure is insufficient. The Optilab rEX needs at least 20 psi of pressure sensed by its gas pressure sensor to set the temperature lower. To dissolve any air bubbles, flow degassed solvent through the Optilab rEX in purge mode. Also, for sub-ambient operation, slowly flow dry gas into the cool thermal environment to prevent water vapor from condensing on the electronics or optics.

Wyatt Technology Optilab rEX Specifications

General

Brand	Wyatt Technology
Model	Optilab rEX
Category	Laboratory Equipment
Language	English

Summary

About the Optilab rEX

Methods of Measuring Refractive Indexes

Explains the deflection-based design and advancements in dRI measurement technology.

Using This Manual

Outlines the organization of the manual and the content of each chapter and appendix.

Contacting Wyatt Technology

Provides contact details for technical support and inquiries regarding the manual and instrument.

Instrument Description

Overview

Describes how the Optilab rEX measures dRI and aRI, its light source, and temperature control.

Front Panel

Details the front panel components including the LCD display, keypad, and fluid connections.

Rear Panel

Describes the rear panel connectors for power, signals, Ethernet, and nitrogen purge.

Quick Start

Setting Up the Optilab rEX

Provides step-by-step instructions for initial instrument setup, including power, temperature, and fluid connections.

Installation and Setup

Power and Signal Connections

Details the rear panel connectors for power input, signal connections, and communication interfaces.

Fluid Connections

Specifies tubing recommendations and connection procedures for sample fluid flow.

Dry Nitrogen Connection

Explains the procedure and requirements for using dry nitrogen for condensation prevention.

Power On and Warm Up

Guides users on powering on the instrument and the necessary warm-up period for stabilization.

Purging the Optilab rEX

Describes the process of flushing the instrument's flow cell with solvents to prepare it for measurements.

Instrument Stability Check

Outlines the procedure for verifying instrument stability before performing measurements.

Using the LCD Display

Navigating the Optilab rEX Tabs

Explains how to use the keypad to navigate through the instrument's LCD display tabs and fields.

Main Tab

Describes the Main tab for viewing dRI or temperature data, and setting instrument parameters.

aRI Tab

Details the aRI tab used for viewing the absolute refractive index of the solvent in the flow cell.

Alarms Tab

Explains how to view alarm states and configure external alarm settings on the Alarms tab.

System Tab

Describes the System tab for configuring settings like waste/recycle activation, time, and light source.

Communications Tab

Details the Communications tab for setting up network and computer communication parameters.

Off-Line Measurements

Instrument Calibration for dRI

Provides detailed procedures for calibrating the instrument for differential refractive index (dRI) measurements.

dn/dc Measurement

Explains how to calculate the dn/dc value from Optilab rEX data and provides measurement guidelines.

Instrument Calibration for aRI

Guides users on verifying and calibrating the absolute refractive index (aRI) measurement of the instrument.

Absolute Refractive Index Measurement

Describes how to perform absolute refractive index measurements, requiring liquid in both chambers.

In-Line HPLC Detection

Conditions for In-Line Operation

Recommends conditions for successful in-line operation, including solvent preparation and thermal control.

Sample Preparation

Provides guidelines for sample preparation to ensure clean solutions and optimal separation.

Measurement

Outlines the steps for performing measurements after sample preparation, including baseline stabilization.

Service and Maintenance

Replacing the LED/Fiber Light Source

Provides detailed, step-by-step instructions for replacing the instrument's LED/fiber light source.

Cleaning After a Fluid Leak

Guides users on how to clean the instrument's liquid leak well after a detected fluid leak.

Cleaning the Air Intake Filter

Explains the procedure for periodically removing and cleaning the instrument's air intake filter.

Changing a Fuse

Details the steps required to safely replace fuses located in the power connection socket.

Optilab rEX Firmware Upgrades

Instructs users on how to check for and obtain the latest firmware upgrades for the instrument.

Troubleshooting

Low Light Alarm

Addresses causes and solutions for the low light alarm condition, related to light intensity issues.

Temperature Will Not Set Below 20 C

Explains why the temperature may not set below 20°C and the role of dry gas pressure.

Noisy Baseline

Provides steps to identify and resolve issues causing excessive baseline noise in measurements.

Microsoft Windows Encounters Problems

Describes how the instrument handles operating system freezes or crashes and how to recover.

Acronyms and Abbreviations List

Acronyms and Abbreviations

Lists and defines acronyms and abbreviations used throughout the user manual.

Operating Principles and Theory

Basic Principles

Explains the fundamental principles of differential refractometry and the conventional flow cell design.

Measurement of the Beam Deflection Angle

Details how the instrument measures beam deflection angle using photodiode arrays and beam positioning technology.

Optilab rEX Specifications

Specifications

Lists the key technical specifications, including range, sensitivity, fluid volumes, and power requirements.

Wire Colors

Earlier Cable Revisions

Provides information on wire colors for earlier revisions of general-purpose cables.

Instrument Connectivity

Introduction

Introduces the topics covered in the appendix regarding connecting the instrument to a computer.

Components Used

Identifies the necessary components for establishing instrument connectivity, including ports and cables.

Connecting to a LAN

Provides instructions for connecting the instrument and computer to a Local Area Network (LAN).

Connecting via USB

Details methods for connecting the instrument to a computer using USB connections.

Connecting via Ethernet When Not on a LAN

Explains how to connect the instrument directly to a computer via Ethernet without a LAN.

Instrument Network Settings

Guides users on configuring instrument network settings on the front panel for connectivity.

Accessing Instruments with ASTRA V

Explains how to access and configure the instrument within the ASTRA V software.

Troubleshooting and Diagnostics

Offers troubleshooting steps and diagnostic procedures for connectivity issues between the instrument and computer.

Warnings

List of Warnings

Lists and explains important safety warnings related to electrical hazards, laser products, and fluid handling.

Wyatt Technology Optilab rEX User Manual

Table of Contents