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K61 SERIES STIRRED LIQUID METROLOGY BATHS

The K61 Series is a modular platform of stirred liquid calibration baths designed to deliver precise, repeatable temperature calibrations across a wide operating range. Multiple configurations are available to optimize performance for specific calibration workloads, while maintaining a common control architecture, user interface, and fluid-based metrology approach.

Wide Temperature Coverage

Configurations available from −80 °C to +300 °C, including low-, mid-, and high-temperature systems, as well as a dual-well wide-range configuration.

High Stability and Uniformity

Actively stirred liquid environment with continuous circulation minimizes spatial gradients and supports high stability over defined measurement intervals.

Precision PRT-Based Control

24-bit AC-excited, ratiometric measurement system using platinum resistance thermometers for accurate and stable control.

Configurable System Architecture

Available as K61L, K61M, K61H, and K61 Wide Range, with optional deep-well (“D”) variants for increased immersion depth.

Advanced Cooling Technology

Our low- and mid-temperature systems utilize a free-piston Stirling cooler charged with Helium (GWP = 0), eliminating the need for conventional refrigerants.

Low Maintenance, High Reliability

Seal-less stirring system and integrated fluid management features reduce maintenance and support long-term operation.

Automation-Ready Operation

Optional remote interfaces enable integration into automated calibration systems, increasing throughput and reducing operator involvement.

(see numbered callouts in image)

Well Opening Ø 2.6″ (65 mm)
Provides ample working diameter to accommodate a wide range of probes and sensors, including liquid-in-glass (LIG) thermometers.
Coaxial Counter-Flow Design
Thermally conditioned fluid circulates upward through the inner calibration volume and returns through an annular channel, providing continuous mixing and supporting stability better than ±0.003 °C over 30 minutes.
Bottom-Stirring Wet Rotor Impeller
Integrated brushless DC motor with wet rotor design eliminates dynamic shaft seals while providing excellent axial and radial uniformity (better than ±0.005 °C).
User-Controlled Motor Speed
Adjustable stirring speed allows optimization of flow conditions for different fluids, loads, and calibration requirements.
Integrated Expansion Volume
Accommodates fluid expansion and contraction across operating temperatures, reducing overflow risk and minimizing user intervention.
Elevated Fluid Level Above Cabinet Top
Bath fluid level is maintained above the cabinet top, enabling convenient calibration of liquid-in-glass (LIG) thermometers and other immersion devices.

Key Features

SYSTEM SPECIFICATIONS

  
    Low Temp
    Mid Temp
    High Temp
    Wide Range
  
    System Setpoint Range
    -80°C to +70°C
    -40°C to +125°C
    +50°C to 300°C
    -80°C to 300°C
  
    Control Stability
    Better than ±0.006°C over 30 minutes
  
    Axial Gradients
    Less than 0.003°C in inner well
  
    Setpoint Resolution
    0.01° (C or F)
  
    Setpoint Accuracy
    Better than ±0.3°C in inner well
  
    Calibration Volume
    
      300 Series Stainless Steel

      ≈2.9” (74 mm) I.D.

      ≈12” (30.5 cm) deep

      ≈18” (45.7 cm) deep (K61D Models)
    
    Power Requirements
    
      120 / 240 Volts

      10 Amps max.

      A.C. 60 Hz
    
    Cabinet Dimensions
    
      18” (46 cm) wide

      20” (51 cm) deep

      36” (92 cm) high

      42" (107 cm) high (K61D Models)