AFS Foundry Sand Testing Equipment Operating Instructions Manual

RIDSDALE-DIETERT MOISTURE TELLER (cont’d)IIDESCRIPTION (cont’d)The thermostat is calibrated 0-9 and is normally set to cover the range 90 °C – 170 °C.Three sample pans are supplied so that while one sample is cooling another can be dryingand the third can be weighed.At the base of the instrument a spring loaded pan holder locates the sample pan in position.This can be adjusted to accommodate 1 inch (25 mm), 2 inch (50 mm) or 4 inch (100 mm)deep pans according to the bulk of the sample under test. 2 inch (50 mm) deep pans arerecommended for foundry sands and this is the standard size supplied unless otherwiserequested.The three sample pans have a fine Hollander cloth base supported by perforated tinnedsteel sheet. This is suitable for all materials except very fine powders.Additional items include an aluminium cooling stand for rapidly cooling the sample in the panand a pair of special tongs for handling hot pans.IIIINSTALLATION(a)(b)(c)This instrument is designed to operate on a standard 3 ft (1 m) high laboratorybench. If the bench has a wooden surface it is desirable to stand the blower unit ona sheet of insulating material to prevent any possible damage to the surface if it isoperated without the sample in position.Connect to an appropriate power supply (see label for correct voltage and frequency)using the moulded plug and 2 metre lead which are supplied.Rotate time switch knob clockwise and check that the blower motor is rotating freelyand that warm air is blown out of the base of the unit (when the instrument is cold itwill take about one minute to warm up). It is important to ensure that the blower isforcing air over the heating element when the power is on. There must be anunrestricted flow of air into the blower unit.IVTEST PROCEDURE(a)Set the thermostat to the required drying temperature. Suitable settings for variousmaterials are given below :-Thermostat SettingTimeSand gravel, etc 7 2 minutesYarn 3 5 minutesGelatin 2 12 minutesCoal 6 6 minutesSinter (crushed) 6 4 minutesSoap Powder 5 6 minutesMetal Powder 5 4 minutesSalt 5 6 minutesHay 5 15 minutesMilk (dried) 4 10 minutesCoconut (shredded) 1 5 minutesIron ore (crushed) 6 8 minutes30