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Mixer Torque Rheometer 3

Caleva Mixer Torque Rheometer

The Caleva Mixer Torque Rheometer (MTR) provides a quick and easy way to quantitatively measure rheological properties of a wet mass in terms of the torque produced when shearing the wet mass within a mixing bowl.

Applications of the MTR:

The MTR has applications for research, formulation/process development and process scale up studies. The MTR is also a useful for off-line monitoring of production excipient screening and quality control.


The Caleva MTR is designed to provide a robust practical rheometer suited to both laboratory and production/quality control environments. The instrument is rapid in use, simple to operate and generates accurate, reproducible results providing an objective, efficient and precise quantitative description of the wet mass.

In practice, the MTR is used to determine the correct Binder:Powder ratio and proper mixing time for wet masses. The amount of binder added to powder to make the wet mass, together with the mixing time, affects the final characteristics and performance of pharmaceutical formulations. With the MTR, pharmaceutical formulations can be efficiently optimized with small amounts of material before extrusion-spheronization, or other processes, are undertaken.

Experimental Modes:

The instrument provides three experimental modes: Consistency, to compare various experimental batches of material; Multiple Addition, which is used to determining the correct Binder:Powder ratio; and Variable Mix Time to determine to the proper mixing time. Experimental data are displayed as tables and as graphs on the attached computer. Data can be exported to a spreadsheet program for further analysis. Graphs from multiple experiments can be superimposed on a single screen so results can be easily compared. The instrument is programmed to mix the material for user-defined lengths of time and prompts the user to periodically add the liquid binder to the mix when required. This process can be automated if the Automatic Liquid Binder Addition option is purchased.

How Does The MTR Work?

The MTR consists of a mixing bowl containing two horizontal, contra-rotating mixing blades. The mixing action of the wet powder mass generates a torque directly related to the consistency of the material in the bowl. The torque applies force via a moment arm to a load cell which records the force.


In short, the instrument has potential wherever wet masses are used and particularly in the pharmaceutical industry, food processing and baking, cosmetics, pesticide, and agricultural and chemical industries.



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Please call us at 732-249-6900 (Eastern US Time) if you would like more information on this product.

  • Dramatically increase the speed at which formulations can be developed and tested.
  • Optimize formulations to compensate for batch variations between excipients.
  • Quality Assurance (Q/A) measurements can be made on excipients.
  • Produce quantitative data that can be used in a structured scaleup program for process development.
  • Routinely batch test a batch for consistency in a few minutes.
  • Quantify the relationship between formulations with different binders and mixing times.
  • Perform quantitative measurements on your formulation.
  • Perform mix comparison studies on your formulations.
  • Study the rheological properties on small samples before committing to large batch sizes.
  • Small sample size 15-30 grams. Especially useful if the material is very expensive or potent. An optional half-Size mixing bowl and blade set is available for smaller batch sizes.
  • Graphs from different experiments can be overlaid to compare results.
  • Rapid results.
  • Rapid data acquisition and manipulation using NI LabView® software.
  • Operating parameters are directly controlled by the user.
  • Easy-to-clean demountable bowl and blade assembly.
  • Data can be exported to a database or spreadsheet program.

Specifications Caleva Mixer Torque Rheometer

Sample Size (Standard Mixing Bowl) 15-30 grams
Moment Arm Assembly: Ranges to 5 Nm fitted as standard.
Load transducer: Ranges to 5 kg fitted as standard.
Data Collection: National Instruments Labview ® based software running on Windows 7 laptop for graphical display, storage and management of experimental data. Experimental data can be exported to spreadsheet for further analysis.
Experimental Procedures: Consistency,
Multiple Addition,
Variable Mix Time
Operation and Controls: HMI on Windows 7 laptop; Power, Safety Status, Motor On lights; Emergency Stop button; Power On switch.
Speed (RPM): Infinitely variable with primary mixing blades rotating from 10 to 250 RPM. Secondary mixing blades are geared to rotate at twice the primary mixing blade speed.
Utilities: Single Phase 110/120, 220/240 VAC, or according to customer requirements.

Hot/Cold running water if optional jacketed bowl is purchased.

Data Connection: 1 X USB port to connect to computer.
Materials of Construction: Cabinet is brushed 304 stainless steel; contact parts are 316 stainless steel; interlocked safety cover is clear Perspex.
Footprint (mm): 450 L x 500 W (without required computer and other optional accessories)
Unit Weight: 35 kg

Specifications may be subject to change without notice.

  • Jacketed bowl heating/cooling system for accurate temperature control.
  • Heating/Cooling unit for water jacket.
  • Automatic binder addition upgrade to fully automate the binder addition process.
  • Half size bowl and blade set for even smaller quantities.
  • Extrusion head option for small scale screw extrusion trials.
  • Software upgrade for 21 CFR Part 11 compliance.
  • Certified calibration weights.
  • IQ/OQ Validation Documentation.
  • Commissioning and training services.