Thermostatic Water Bath For Viscometers

The Method:

• A manual bath is used for the determine the kinematic viscosity of transparent liquids and opaque liquids.
• The time is measured for a fixed volume of liquid to flow under gravity through the glass capillary of a calibrated viscometer at a closely controlled and known temperature.
• The kinematic viscosity (determined value) is the product of the measured flow time and the calibration constant of the viscometer. Two such determinations are needed from which to calculate a kinematic viscosity result that is the average of two acceptable determined values.
• Depending on the sample type and individual preferences a viscometer type has to be selected.

Standards:

• Standards: ASTM D445, ASTM D446, ASTM D1655, ASTM D2170, IP71, EN ISO 3104, ISO 3105, and DIN 51562.
• The test method describes the manual determination of kinematic viscosity.
• Measure the time for a volume of liquid, transparent or opaque, to flow under gravity through a calibrated glass capillary viscometer (please see ASTM D445 & D446).

Manual Kinematic Viscosity baths:

Bath Temperature:

·         Use a bath with a constant temperature.      

·         Temperature tolerance max. ± 0.02°C between +15°C to +100°C. Outside this range ± 0.05°C.

·         The temperature measuring device is a calibrated glass thermometer,  accuracy ± 0.02°C or better. Or a Digital Contact Thermometer (DCT) is allowed. We recommend our E20 DCT thermometer with temp. range from 20°C to +120°C 

·         Since October 2017, mercury in LIG thermometers are forbidden in the European Union and the market have to change to DCTs.

Capillaries:

·         The viscometer is a calibrated capillary, the size depends on the sample being tested.

·         Flow times between 200 and 900 seconds are recommended.

·         The viscometer has to be suspended in a vertical position. This is possible with stainless steel viscometer holders. These are available for most of the viscometers, see www.testform.com.tr for more information.

Timing Device:

·         The manual timing device must allow readings with a tolerance of 0.1 second or better. Accuracy ± 0.07%.

·         Electrical timing devices can be used if an accuracy of ± 0.05 % or better is reached.

·         Timer uses a crystal which has a maximum deviation of 20 ppm (parts per million).

·         On one second that is (1 / 1000.000 ) * 20 = 0.00002 sec.

·         One hour has 60*60*0.00002 = 0.072 seconds.

·         Human reaction time is 0.2 second (200 mS).

·         So, fault of timer when measuring one hour is three times less than human error (viscosity flow time is between 200 and 900 seconds).

TV2000 & TV4000 (Main Characteristics):

ü  Temperature Range

ü  Ultra High Stability

ü  Three or Seven Places

ü  LED Lights Background

ü  Detachable Front Window

ü  Bath Drain & Bath Overflow

ü  PID Digital Controller

Temperature range:

·         Standard range from ambient to +230ºC.

·         TV2000 & TV4000 is standard equipped with a cooling coil.

·         When connecting to tap water or an external cooler, sub-ambient temperatures can be reached.

High Temperature Stabilty:

Temperature tolerance max. ± 0.02°C between 15°C to 100°C. Outside this range ± 0.05°C.

Cover with 3 & 7 Positions:

·         The cover of the bath has round 51 Ø mm holes with lids, for suspending glass capillary viscometers in holders.

·         Cover has standard two openings 12.5 mm ø for ASTM thermometers.

·         Cover of TV2000 offers three holes (four optional).

·         Cover of TV4000 offers seven holes (eight optional).

External LED LIGHT:

·         Testform has introduced a new design using LED technology which can be mounted on the TV2000 & TV4000 as a back panel resulting in excellent visibility in the bath.