METTLER TOLEDO
 

Why digital Instruments are better

Density and refractive index measurements have always been popular in the quality control of liquid samples because the determination of the density and the refractive index is, in most cases, the easiest and the quickest way to characterize a liquid or to determine the concentration of one component in two component mixtures. Classical examples of such concentration measurements are sucrose content determinations in sugar solutions (BRIX measurements) by means of a refractometer or alcohol determinations by means of hydrometers.

Yesterday...
An optical Abbe Refractometer and a set of hydrometers or a pycnometer belonged or still belong to the standard equipment of more or less every QC lab. Both the density and the refractive index depend on the temperature. For this reason, one or several thermostats (water baths) formed part of the inventory of most of the labs where densities and refractive indices had to be determined. A density measurement with a pycnometer is much more time consuming than a determination of the refractive index by means of an optical Abbe refractometer. This is probably the main reason why refractometry is still more popular in the quality control of liquid samples than density measurements.
Portable refractometer Refracto 30PX
Now...
The availability of highly accurate digital instruments for the determination of the density and the refractive index made the determination of these two parameters even more popular in the quality control of liquids. The reasons for this are clear:
• Higher accuracy of the results.
• Fewer error sources i.e. less operator
  dependent results.
• Less time required for the measurements.
• No water bath required. Most of the digital
  bench top instruments available nowadays
  have a built-in Peltier thermostat, while portable instruments often have an
  automatic temperature compensation.
• Direct display of the result in the desired unit. Modern digital instruments are able
  to display concentrations directly and to do special temperature compensation of
  the results if required. Measurement data may be printed out or archived in a
  computer.
• Naturally the bench top and portable density meters and refractometers from
  METTLER TOLEDO offer all these advantages.
DR40 combined meter
Tomorrow...
With our latest offering, the combined determination of the density and the refractive index have become even easier.
The fact that density and refractive index measurements are being used more  and more for the quality control of liquid samples has led METTLER TOLEDO to introduce the DR40/45 Combined Meters, instruments that determines both quantities simultaneously.
With the new sample delivery and cleaning units, SC1 and SC30, our density meters, refractometers and Combined Meters perform the measurements at a touch of a button.
These SC units are not only the best guarantee for fast payback of the equipment, they also help to prevent measurement errors and to reduce the consumption of cleaning solutions.