UNITHERM ™ MODEL 1161H
HIGH TEMPERATURE DILATOMETER
- SALIENT FEATURES

(Technical Note #104)

Furnace:

   Compact design
¨ Forced-air cooled shell
¨ Long life Kanthal Super 33 elements (rated to 1800°C)
    Alumina muffle with water cooled muffle flange
    Vacuum port with anti-syphon safety bubbler
    Purge gas capability
· Energy saving design

Power Supply:

    Efficient, cool operation
    Solid state power controller
¨ Water cooled thyristors
    Phase angle and current limiters

Safety:

· Chamber pressure relief valve [Selected Models]
· Water flow interlock sensor
    Open thermocouple protection
¨ Dead computer protection
· Software selectable safety limits
· Logical (in-software) safety features

Dilatometer:

    Counterbalanced stage to lift out dilatometer
    Water cooled instrument platform
    Select-grade alumina dilatometer tube and pushrods (matched construction)
    Easy removal and exchange of sample holder platform
¨ Dual sample (two independent) simultaneous, or differential operation
    Vertical or horizontal configuration
¨ Optional range extension to 1700°C (vertical only)
¨ Critical mechanical parts are fabricated form nearly-zero Invar (no need for expensive constant
    temperature circulators to cool dilatometer head
¨ Counterbalanced push-rod using static weights
·  TMA Operation (optional)
· ¨ Fully digital, absolute displacement transducer
· ¨ Long stroke coupled with high sensitivity, especially useful for sintering work

Temperature Programming:

¨ Digital adaptive temperature control which provides control to true sample temperature
    not to furnace temperature
·  Built in tutorial and simulation program
·  On-screen programming with entry checks, 26 segment program
    Variable heating rates within a broad range
    Variable dwell temperatures, 1° increments
    Variable soak times, 1 minute increments
·  Up to 98 stored programs, with quick review window
·  Up to 9 repeat cycles

Special Programs (Optional):

·  Controlled rate sintering cycles
·  Softening point determination

Data Analysis:

    Fully automatic, computer controlled data reduction according to ASTM E228 procedures
·  Statistical evaluation of data and curve fitting
·  Computation of results in uniform intervals
      Percent expansion vs. temperature table
      Average coefficient vs. temperature table
      Instantaneous coefficient vs. temperature table
      Percent expansion vs. temperature plot
      Average coefficient vs. temperature plot
      Instantaneous coefficient vs. temperature plot
· ¨ Automatic calibration cycles with multiple (stored) calibration files