Ray-Ran – Auto Density Measurement System

Quick and accurate density measurement

The Advanced Auto Density Gradient Apparatus from Ray-Ran has become the world’s benchmark for accurate density measurement of small solid specimens using the column method.  

Built with operator simplicity in mind, its ease of operation and high accuracy makes it ideal for density testing during product development and quality control within production, research and development labs and teaching institutions. 

Built in temperature control 

Our Auto Density Measurement apparatus is supplied with built in digital temperature control to ensure the temperature of each column is at 23°C+/- 0.1°C. For ambient temperatures in excess of 23°C the integrated cooling coil can be used in conjunction with an optional water chiller unit so the correct temperature can be maintained. This can be even more accurately controlled using the optional microprocessor-controlled water flow valve kit. 

How to use the density measurement system

Available as a 3 or 6 column version, the built-in on-board Microprocessor System accurately calculates the specimen’s density to a resolution of 0.001g/ml more quickly and more accurately by measuring the samples position in the column relative to the calibrated marker floats. Once the correct position of the sample is recorded, the density is displayed on the LCD screen. Column linearity can also be checked and shown in Techni-Test software. 

The gradient column method

Density gradient columns are a way of determining the density measurement of polymers, resins, plastics and more.  

Building a column 

To build a column, a peristaltic pumped filling system is supplied with the Advanced Auto Density Gradient Apparatus from Ray-Ran Column filling speeds are variable from 0.5l/hr to 1.5l/hr.  

The resulting solution has a density which, when introduced into the column, increases uniformly from top to bottom. Calibrated glass marker floats with known densities are introduced into the column and sink to a point where their density matches the solution.  

Microscopic sighting 

A linear encoder which is attached to a trammel guide is used to calibrate the gradient of the column by focusing the optical microscope onto the center of the calibrated float and entering the floats density value into the microprocessor. Once test samples have been introduced into the column and have reached a point of static equilibrium, they are accurately sighted using the microscope.  

The resultant density of the sample is obtained and displayed on the LCD without the need for complicated graphs. An automatic sweep mechanism is used to extract the floats and samples from each column.  

Data analysis with Techni-Test software

The on-board LCD provides simple on-screen instruction and using the alpha/numeric keypad test parameters, such as operator list, material reference numbers and batch numbers, can be entered and stored for results presentation. Batch statistics of mean, standard deviation and co-efficient of variation are automatically updated after each test and results are shown in graphical and tabular format for analysis when downloaded to the supplied Techni-Test PC software. 

Optional Ancillaries:

Glass marker floats 0.7g/ml up to 2.2g/ml 

Microprocessor controlled filling system 

Digitally controlled water chiller 

Basic manual water chiller unit