TESTING WEIGHTS

New Zealand Herald, Volume LXXIV, Issue 22621, 8 January 1937, Page 12

TESTING WEIGHTS

WOEK IN AUCKLAND | THOUSANDS OF CHECKINGS PETROL PUMPS AND BOTTLES In the past year the Weights and Measures Department in Auckland, which operates over that portion ot the Auckland Province north ol 'lhaines, including the Coromandel l'eninsula, inspected and checked over 1100 petrol pumps and over 125.000 milk and oil bottles, and also tested over 1000 weighing instruments and nearly 9000 u eights. These figures give an impressing indication ot the work done by the department in Auckland, but they give very far from the whole story. Ihe inspection of petrol pumps is an annual affair. In the first place, no petrol pump can operate until the head office in Wellington has approved of the design. These ban; been in process ol considerable change. Originally petrol pumps were manually operated. and before a motorist got lull measure the hose had to be emptied. Hut meter pumps, operated by a motor, are last taking their place, and in these the hose is always full, so that the motorist, if the measuring apparatus is in good order, must get the correct measure. Another design now being installed also computes the price on a dial lace. '1 he plans of the mechanism ol the modern petrol pump are very intricate, and | the inspector has to make hiiusell

familiar with these l),v means of a scries of prints supplied from Wellington. Inspections carry a fee, and lor the typo of pump that also computes the price the charge is 15s, against 10s for the ordinary typo. Safeguards with Milk An inspector lias to ho a man of considerable mechanical knowledge. For example, il any new types of weighing devices are imported, reports on thoso have to he made to the head ollice, which approves or otherwise oi such machine.-:. When the milkman pours out the milk he does so from a measure tested by the department. If the milk is handed over to the householder, the receiver can be certain that the bottle container has also been officially tested. Before the glassworks at Penrose puts out a batch of milk bottles, an inspector checks each one. .Just inside the neck of the bottle is small beading against which normally the cardboard stopper is pressed. An eighth of an inch below that is the datum line, up to which tlie fluid niusi come. An allowance is made for error, either of deficiency or excess, in the container up to one drachm. All scales in public use are, of course, tested. This may be a feature of modern trade, but the ancients wore just as scrupulously insistent on true measures. One officer of the department carries in his pocket book these lines from the .Book of Proverbs: —"A false balance is abomination to the l/ird. but a just weight is His delight." And these lines are in bis inside coat pocket, whether he is testing^minute scales for a laboratory, or one'of the Harbour Board's 20-ton weighbridges, which with other weighbridges in Auckland arc tested annually. For the testing oi these weighbridges the department keeps ti stock of five tons in 501b. weights. These weights are themselves tested once a year, for they become worn with handling and periodically have to be replaced.

Varied Duties Another duty 011 which inspectors arc regularly employed is in testing the weights of certain foods, such as butter, tea, sugar and coffee, which are sold in packets. By legislation such provisions must bo sold at standard weights, t oal carts arc often accosted by inspectors, who carry with them scales for weighing sacks of coal to see if they conform to the regulations. Another duty is to test various measures lor tinsmiths and other manufacturers before their goods arc supplied to the public. The Weights and .Measures Department has many shelves containing weights and measures, often of copper, bronze or brass. These are never polished, for they would then lose weight. There is actually a loss of weight by corrosion, and so.at intervals they are tested by the head ollice in Wellington. Some of the weights ami measures used by the experts in Wellington are never handled, being picked up by tongs in order to prevent loss by wear. Standard Measures But even the department's measures in Wellington have to he tested at times, and there is legislative, provision for this being done. The standard pound and yard measures are sent to Kngland to see that they are exactly equal to the Imperial standard pound or standard yard measure. The pound measure used in England is a cylinder of platinum, which does not corrode, and it. is always lifted by an ivory fork, the edges of which are carefully rounded off. The standard yard measure is a solid bar of bronze, into which are set two gold plugs, the centres of which are ,36in. apart. The temperatures at which the tests are made have an important relation to the result. The grdlon is (he standard measure of capacity from which all other measures for liquids or dry goods are derived, and it may therefore be of interest to state that (he standard for the gallon is ten Imperial standard pounds of distilled water, weighed in air against brass weights with water and air at 62 degrees l'\, and with the barometer fit 'Win. These details rather go to show that there is no more exact science than that of measuring, which is the basis of most of the sciences.