K39200 Water Separability Tester


Test Method
The ability of a lubricating oil to separate from water and resist emulsification is an important performance charcteristic for applications involving water contamination and turbulence. Water separability is determined by stirring equal volumes of water and sample together at a controlled temperature to form an emulsion and observing the time required for separation of the emulsion to occur. This method is suitable for petroleum oils and synthetic fluids.

Features and Benefits
• Tests emulsion characteristics of lubricating oils

• Seven sample capacity

• Movable digital stirrer with microprocessor control incorporates advanced features for flexibility and ease of operation

• Clear, illuminated heating bath provides excellent visibility

• Microprocessor temperature control with digital display and built in protection against over-temperature and low liquid level hazards

• Conforms to ASTM, ISO and related standards for water separability testing

• Optional sensor for direct measurement of sample temperature


K39200 Water Separability Tester
Seven sample Water Separability Tester provides full visibility and microprocessor control of all functions for simplified, accurate testing of up to seven samples at a time. Use for specification of new oils and monitoring of in-service petroleum oils and synthetic fluids.

Seven position heating bath – A full visibility bath immerses seven 100mL cylinders at the proper depth per ASTM and ISO specifications. Sample cylinders are held securely in place by stainless steel supports inside the bath. A microprocessor based immersion circulator/heater assembly controls bath fluid temperature with greater than 1C accuracy and stability throughout the operating range of 25C to 150C. Large LED readouts display setpoint and actual temperatures in celsius or fahrenheit scale at the operator’s option. For most samples, ASTM/ISO sample temperatures of 54C and 82C are attained within 10 minutes after placement of the test cylinders into the stabilized bath. Clear Pyrex™ bath has backlighting for excellent visibility when viewing emulsion separations in the test cylinders. Cut-off circuits for low water level and over-temperature conditions provide protection in the event of equipment malfunction. Finished aluminum cover assembly has built-in handles for removal when filling or cleaning the bath.

Microprocessor sample stirrer – To avoid sample movement, the sample stirrer housing pivots to each test position in the bath and locks securely in place at the required position in relation to the 100mL sample cylinder. The digital stirrer offers complete flexibility for test duration and stirring speed at the push of a button. Operating speed and count down time are prominently displayed on a large backlit LCD panel. A wide operating range of 60 - 1800 rpm permits in-house customized testing with 1rpm accuracy, and the operator may select a stirring time of up to 99.99 minutes. At the end of the selected interval, the stirrer automatically shuts off and alerts the operator with visual signals that the settling period has commenced. For added convenience, all test parameters are stored in memory and repeated in subsequent tests until they are changed by the operator.

Conforms to the specifications of: ASTM D1401, D6074, D6158; ISO 6614; DIN 51599; FTM 791-3201

Stirrer Range: 60-1800rpm

Accuracy: 1.0rpm

Drive: 1/10hp (75W), high torque

Bath Temperature Range: 25C to 150C

Control Stability: 0.05C

Capacity: seven (7) 100mL graduated cylinders

Construction: Pyrex™ glass jar 12x12 in. (30.5x30.5cm)

Medium: Water or white technical oil

Medium Capacity: 21.9L (5.8 gal)

Electrical Requirements
115V 50/60Hz, 12A
220-240V 50/60Hz, 6A

Included Accessories

Seven 100mL Cylinders

12x12x38 (30.5x30.5x96.5)
Net Weight: 55 lbs (24.9kg)

Shipping Information
Shipping Weight: 85 lbs (38.5kg)
Dimensions: 8.4 Cu. ft.

Ordering Information



Product Description

Electrical Requirements


Water Separability Tester

115V 50/60Hz


Water Separability Tester

220-240V 50/60Hz



Catalog Number

Product Description


Cylinder, 100mL
Graduated from 5 to 100mL with 1.0mL divisions.
(Not suitable for use with discontinued models K39000 and K39096. Contact your Koehler representative for information.)


ASTM 19F Thermometer.
Range: 120 to 134F


ASTM 19C Thermometer.
Range: 49 to 57C


ASTM 21F Thermometer.
Range: 174 to 188F


ASTM 21C Thermometer.
Range: 79 to 87C


PTFE Policeman


Test Tube Rack


When inquiring about NIST traceable certified thermometers, please refer to the catalog number for the corresponding thermometer and replace the middle three zeros in the catalog number with 004. Example: 251-000-01C ASTM 1C Thermometer would be 251-004-01C ASTM 1C Certified Thermometer.