Testing Machines
Testing Machines names 3 different subjects across the 6 encyclopedias on this shelf. Each is set out below.
Testing Machines machines used for the accurate testing of iron
Collier's New Encyclopedia (1921)
machines used for the accurate testing of iron, steel and other materials used in constructive work. The problem which these machines are intended to solve is the adjustment with certainty of a safe margin of strength with a minimum of weight, which can be determined only by experimental tests on full sized sections of the materials used in the construction. One method is to use machines designed to test small sample pieces under such conditions that the breaking strength of the test-piece is measured by the machine, and from the figures thus obtained is calculated the strength per square inch of the full-sized constructive material. A common feature of such machines is the common steelyard balance, supported by knife edges. There are several machines of this class, some of them built up to 100,000 pounds capacity and over. The hydraulic testing machine, invented by A. H. Emery, was originally used at the United States arsenal at Watertown, Mass. The greatest peculiarity of the Emery testing machine is the method by which the stress produced on the piece tested is conveyed to the scale and accurately weighed by mechanism that is entirely without friction, and hence responds to the same increment of load regardless of the amount of strain on the specimen. This result is accomplished by receiving the load against a flat closed cylinder called the hydraulic weighing head. One of the government experi ments with this machine was the breaking by tension of a forged iron link 5 inches in diameter between the eyes, at a strain of 722,800 pounds, and imme- 7 diately after a horse-hair of an inch 1000 in diameter was slowly strained, and, after stretching 30 per cent., snapped under the recorded strain of 16 ounces. TEST OATH, an oath prescribed by the United States Congress July 2, 1862, to be taken by persons in the former Confederate States appointed to office under the National government. The text was as follows: "I, A. B., do solemnly swear (or affirm) that I have never voluntarily borne arms against the United States since I have been a citizen thereof; that I have voluntarily given no aid, countenence, counsel, or encouragement to persons engaged in armed hostility thereto; that I have neither sought, nor accepted, nor attempted to exercise the functions of any office whatever, under any authority or pretended authority in hostility to the United States; that I have not yielded a voluntary support to any pretended government, authority, power, or constitution within the United States, hostile or inimical thereto. And I do further swear (or affirm) that, to the best of my knowledge and ability, I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion, and that I will well and faithfully discharge the duties of the office on which I am about to enter, so help me God." TEST PAPERS, in chemistry, are made by dipping unsized paper into an alcoholic solution of a vegetable coloring matter which changes color when exposed to the action of an acid or alkaline solution. The paper, after being gently dried, is cut into slips of a suitable size. Hence, by dipping the appropriate test papers into any solution, one can ascertain whether it is acid, alkaline, or neutral. Litmus and turmeric are most commonly used as the coloring matters; litmus for the detection of acids, and turmeric for that of alkalies. Test papers are also employed for detecting sulphuretted hydrogen, etc., and for such a purpose the paper must be dipped in the solution of an appropriate substance. Thus acetate of lead paper becomes black in presence of sulphuretted hydrogen, while starch paper becomes blue when touched with iodine. TESTUDINARIA (so named from the resemblance which the great, rugged, cracked root of the plant bears to the shell of a tortoise), in botany, the elephant's foot or Hottentot's bread; a genus of Dioscoreaceæ, akin to Dioscorea, but with the seeds v winged only at the tip, instead of all round. Rootstock above ground sometimes four feet in diameter. Stems occasionally 40 feet long; flowers small, greenish-yellow. T. elephantipes is the common elephant's foot or Hottentot's bread. The rootstock is a large, fleshy mass, covered with a thick bark, cracked deeply in every direction. The Hottentots in time of scarcity made use of the fleshy inside of the root as a kind of yam.
Testing Machines The great variety of testing-machines now in the market
The Encyclopedia of Founding (1892)
The great variety of testing-machines now in the market are an evidence of their growing importance. Wide-awake foundry-men everywhere realize the necessity for strict inspection of all the pig iron the purchase in order that their castings may be made to meet every requirement at the least possible cost. By means of the simplest of these machines, a sample of pig iron can be tested and its quality determined with approximate nearness in an incredibly short space of time, so that purchases need not be made blindfold as has been too frequently the case in the past. A more elaborate system of tests may be obtained by the use of Keep's test, which reveals every phase of a true test with the nicest accuracy: gradual load, impact, fluidity, tendency to curve, shrinkage, and deflection are at once determined by this machine in a manner truly astonishing. The Waterloo Transverse-testing Machine is arranged with the weighing-beam and system of multiplying levers, all tested and regulated in accord with the United States standard of weights at Washington, D.C., and delicately adjusted to weight the strain exerted on the specimen. The power exerting the strain on test-piece is produced by a worm and gear. The best of materials are used, and the workmanship is first-class in every particular. The specimen in process of testing has one end resting upon an A-shaped piece of metal, the other end being suspended from the lower lever of the machine. The strain upon the test-piece is produced by turning a wheel below in front of the frame, which causes the stirrup, which is located at the centre point of specimen, to bear down upon the same, and the strain thus produced is transmitted to the weighing-beam through the intermediate lever. The weighing-beam is kept in equipoise by shifting the poise, the power being applied simultaneously with the movement of the poise, and continuing the operation until the test is concluded. Care must be taken that the weighing-beam is balanced before the testing is begun or the test-piece in position. Additional standard weights are supplied to suspend on the small end of the weighing-beam, as occasion requires, to balance the strain up to the full strength of the test-specimen. This machine can be arranged to test longer specimens up to four or five feet, at extra cost. An indicator to show elasticity of specimens being tested can be added. See TRIAL CAST.
Testing Machines machines used for the accurate testing of iron
Collier's New Encyclopedia (1921)
machines used for the accurate testing of iron, steel and other materials used in constructive work. The problem which these machines are intended to solve is the adjustment with certainty of a safe margin of strength with a minimum of weight, which can be determined only by experimental tests on full sized sections of the materials used in the construction. One method is to use machines designed to test small sample pieces under such conditions that the breaking strength of the test-piece is measured by the machine, and from the figures thus obtained is calculated the strength per square inch of the full-sized constructive material. A common feature of such machines is the common steelyard balance, supported by knife edges. There are several machines of this class, some of them built up to 100,000 pounds capacity and over. The hydraulic testing machine, invented by A. H. Emery, was originally used at the United States arsenal at Watertown, Mass. The greatest peculiarity of the Emery testing machine is the method by which the stress produced on the piece tested is conveyed to the scale and accurately weighed by mechanism that is entirely without friction, and hence responds to the same increment of load gardless of the amount of strain on the specimen. This result is accomplished by receiving the load against a flat closed cylinder called the hydraulic weighing head. One of the government experiments with this machine was the breaking by tension of a forged iron link 5 inches in diameter between the eyes, at a strain of 722,800 pounds, and imme- 7 diately after a horse-hair of an inch 1000 in diameter was slowly strained, and, after stretching 30 per cent., snapped under the recorded strain of 16 ounces.
What Has Changed in the Last Century
When Collier's described these machines in 1921, load was still weighed by knife-edge steelyard balances or by A. H. Emery's frictionless hydraulic weighing head, the pride of the Watertown Arsenal. That mechanical weighing was displaced after the bonded electrical resistance strain gauge appeared in 1938: modern universal testing machines use strain-gauge load cells, servo-hydraulic or electromechanical drives, and computer control, printing a full stress-strain curve rather than a single breaking figure. Just as important, the whole philosophy shifted from Collier's "safe margin of strength" to fracture mechanics and fatigue testing, which explain why a flawed part fails far below its measured tensile strength, and to non-destructive methods — X-ray, ultrasonic, dye penetrant — that inspect the actual finished piece instead of a sample of it. The foundryman's rule-of-thumb pig-iron tests praised in 1892 have likewise given way to spectrometric chemical analysis and to standardised procedures written down by bodies such as ASTM.
Written for this edition, 2026.