Viscosity The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the informal notion of "thickness". For example, honey has a higher viscosity than water. A viscometer (also called viscosimeter) is an instrument used to measure the viscosity of a fluid. For liquids with viscosities which vary with flow conditions, an instrument called a rheometer is used. Viscometers only measure less than one flow condition. In general, either the fluid remains stationary and an object moves through it, or the object is stationary and the fluid moves past it. The drag caused by relative motion of the fluid and a surface is a measure of the viscosity. The flow conditions must have a sufficiently small value of Reynolds number for there to be laminar flow. At 20.00 degrees Celsius the viscosity of water is 1.002 mpa s and its kinematic viscosity (ratio of viscosity to density) is 1.0038 mm2/s. These values are used for calibrating certain types of viscometer. A fluid that has no resistance to shear stress is known as an ideal fluid or in viscid fluid. Zero viscosity is observed only at very low temperatures, in super fluids. Otherwise all fluids have positive viscosity. If the viscosity is very high, for instance in pitch, the fluid will appear to be a solid in the short term. A liquid whose viscosity is less than that of water is sometimes known as a mobile liquid, while a substance with a viscosity substantially greater than water is called a viscous liquid.
U tube viscometer These devices are also known as glass capillary viscometers or Ostwald viscometers, named after Wilhelm Ostwald. which consists of a U-shaped glass tube held vertically in a controlled temperature bath. In one arm of the U is a vertical section of precise narrow bore (the capillary). Above this is a bulb, with it is another bulb lower down on the other arm. In use, liquid is drawn into the upper bulb by suction, then allowed to flow down through the capillary into the lower bulb. Two marks (one above and one below the upper bulb) indicate a known volume. The time taken for the level of the liquid to pass between these marks is proportional to the kinematic viscosity. Most commercial units are provided with a conversion factor, or can be calibrated by a fluid of known properties. The time required for the test liquid to flow through a capillary of a known diameter of a certain factor between two marked Kinematic viscosity bath Viscosity Bath are useful for measuring the viscosity of petroleum & oil applications. This Viscosity Baths are used for precise temperature applications with capillary viscometers and density meters within the bath tank. The units offer high temperature accuracy and optimal temperature distribution throughout the bath. Inner chamber made out of S.S 304 & outer chamber made out of M.S sheet duly powder coated. Microprocessor based PID controller cum indicator with dual digital display for showing set value & process value. An integral cooling coil for cooling water is provided for temperature applications below or near ambient temperatures (optional). The units are equipped with a holder for thermometers and therefore offer very good options for temperature calibration procedures and comparisons with accredited thermometers.
Redwood viscometer no : 1 & 2 These viscometers are designed for viscosity tests of petroleum & oil products which react as Newtonian liquids at the test temperature. They confirm to requirements of IP 70. Two adaptation of Redwood Viscometer are available. No. 1 for liquids having Redwood flow 20 seconds to 2000 seconds and No. 2 for liquids whose flow time with No. 1 exceeds 2000 seconds. The complete outfit comprises stainless steel bath having drain plug with Electrical heating arrangements which is operating at 220 Volts 50 Hz AC Mains power supply or Gas Heating arrangements with tap, silver plated oil cup with precisions stainless steel jet, ball valve, cover, thermometer clip, stirrer and suitable stand with leveling screws. Engler viscometer Rasayan engler viscometer is designed as per IP 212 and ASTM D 490. It is useful for determining the Viscosity of lubricating and fuel oils. This viscometer is composed of main unit & control unit. It Consists Stainless Steel Water Bath having Oil Cup with lid. The water Bath with Stirring device mounted on stand. A Thermometer clip to the Water Bath and the Oil cup lid has a thermometer Socket. The bath is fitted with suitable sized Heater. This unit can operate on 220 volts AC power supply. Digital model with PID temperature controller cum indicator also available at extra cost.
Tar viscometer TAR viscometer is used for determining the viscosity of cut-back bitumen and road oil. The apparatus, housed in a stainless steel case or chrom plated copper sheet, consists of a tank with 10 mm or 4 mm orifice& ball lifting clip. The bath fit with a thermostat, an agitator, an immersion heater to take the water to the required temperature with energy regulator at extra cost and cooling coil for connection to the water supply. (Optional).The temperature is checked by a 0-45 C thermometer. The apparatus is supplied with metal cup cover and stopper holder. Cups to be ordered separately. This unit requires 230V, single phase AC power supply. The tar viscometer is also available for multiple test fitted with digital temperature controller cum indicator fitted with motorized stirrer with tar cup of 10mm or 4mm orifice Flow cup viscometer Flow cup viscometers provide kinematic viscosity data. Flow cup is made by brass or aluminum casting the orifice made of S.S The measured kinematic viscosity is generally expressed in seconds (s) flow time when the fluid is flowing through an orifice at a specified temperature. Thanks to the conversion equations the viscosity is calculated from the flow time to centistokes (cst). The calibration certificates are supplied with the cups at extra cost. According to the different standard there are many types of flow cup available. The cups can be supplied with specific stand or without stand.
Saybolt viscometer Saybolt viscometer is a device used to measure the viscosity of a fluid. The saybolt viscometer is control the heat of the fluid and the viscosity is the time takes the fluid to fill a 60cc container. saybolt Viscometer determines viscosity of petroleum liquids at temperatures from ambient to 240 C. PID controller maintains ±0.1 C temperature uniformity throughout operating range and provides quick temperature stabilization with protection of an overtemperature control. Set-point temperatures are displayed in F/ C. Circulate tap water or refrigerated coolant through the built-in cooling coil for operation at nearambient temperatures. The apparatus consists of stainless steel bath with oil cup which is centrally placed in a water bath. The bath has a lid which contains a water cooling tube, two handles with two stirring blades, thermometer socket and a straight heater. Stirring is done by turntable arrangement. A thermometer can also be inserted into the cup cover. Two jets one universal and one furol can be screwed to the cup by a handle (without strainer, withdrawal tube and glassware) The temperature is controlled by energy regulator.(extra cost) Suitable to work on 220V,50 Hz, AC single phase. Mfg.by HOLY SCIENTIFIC C-2 (6) plot no: 67/3 phase 1 GIDC estate, vatva, ahmedabad-382445 Contact : 091-040085092/93/94 Mobile : 091-09427000891/09925007572 Email : holyscientific@gmail.com Uday_parekh@hotmail.com