To make a test, the following apparatus and instruments are necessary:
1. Scales to weigh the coal.
2. Apparatus to weigh or measure the feed water.
3. Thermometers to take feed-water temperature.
4. Gages to indicate steam pressure.
A boiler test to be of value should extend over a period of at least eight hours. The longer the test the more accurate the results.
[1] For the sake of simplicity, only the essential elements of boiler and furnace testing are treated in this bulletin. For rules covering the refinements for an exhaustive test, the reader is referred to the boiler test code of the American Society of Mechanical Engineers. Copies of this code can be obtained from the secretary, 29 West Thirty-ninth Street, New York City.
WEIGHING THE COAL.
The weight of coal used during a test may easily be found by using an ordinary wheelbarrow and a platform scales, arranged as in figure 1. At each side of the scales build an incline with its top level with the top of the platform, but take care not to have either one touch the platform. Set the empty wheelbarrow on the scales, run the movable weight or poise out until it exactly balances the weight of the barrow and lock it in position with the thumbscrew.