Parts per million or grains per gallon are the most common. One part per million (PPM) is just what it says: out of one million units, one unit. Grains, or grains per gallon (GPG) is a weight measurement taken from the Egyptians; one dry grain of wheat, or about 1/7000 of a pound. It takes 17.1 PPM to equal 1 GPG.

The hardness of a PVC compound is measured by using a durometer tester. This instrument consists of a dial gauge with a needle point. When the needle is pressed into the material, a reading is obtained on the gauge that indicates the hardness. The most common reading is based on a 15 second delay. See similar questions...

We use microhardness test at 100 or 50 mg load to measure hardness at various depth and then determine effective case depth. See similar questions...

We can measure Vicker's Hardness by MICRO VICKERS HARDNES TESTER with 50 or 100 gm load after mounting the specimen in Plastic Mould. The charges per sample will be Rs. 400/- plus 12.24 Service Tax and we will report hardness by 3 indentations. Please mark the location where hardness is needed. Mechanical Strength means one of several tests including Impact, Hardness, Compression, Fatigue, and more. See similar questions...

Early pedometers were mechanical and used a moving lever arm to count steps. Electronic pedometers now detect movement through a spring loaded, counter-balanced mechanism that records vertical acceleration at the hip. Pedometers measure the number of steps a person takes throughout the day. See similar questions...

Hardness is a measure of the amount of calcium and magnesium minerals in water. Groundwater typically has a higher mineral content than surface water. A high concentration of minerals in the water can make it hard to lather, hence the term “hard water.” Soft water, on the other hand, has a low concentration of minerals, and requires extra rinsing to remove soap. Our water is moderately soft, with 65 milligrams per liter of hardness. See similar questions...

If you are connected to a municipal supply, call the water Superintendent, or City Hall. They can either provide the answer, or direct you to the proper individual. Remember the conversion factor: it takes 17.1 PPM to equal 1 GPG. In other words, if your water has 171 PPM calcium in it, divide 171 by 17.1 to get the answer in grains. This example would be 10 grains, or GPG. See similar questions...

Macrohardness is in the 64-70 HRC range for WC 200, 60-66 HRC for WC 210 and 56-62 HRC range for WC219. However, our claddings are a composite of tungsten carbide particles dispersed in a nickel-based alloy matrix. The extremely hard carbide particles, with a Vickers Diamond Pyramid Hardness of about 2000 DPH50g (1865 DPH50g is equivalent to 80 Rockwell C Hardness (HRC)), are surrounded by a two-phase matrix (300-800 DPH50g, equivalent to 30-64 HRC). See similar questions...

The molecular electronegativity and hardness are generalizations of the same concept at the atomic level: See similar questions...

ColorScan? recognizes up to five colors simultaneously. Three groups of five different colors are recommended for multiple shift operations. The crayon hardness required depends largely upon ambient mill temperatures and wood surface conditions. Lucidyne has installed over 450 GMRs world-wide and will recommend crayon colors and hardness prior to installation. The GMR can control a grade stamper, although this function is normally controlled through trimmer or sorter controls. See similar questions...

Keep your calcium hardness levels between 200-400 ppm. A level that is above this may find it easy to precipitate out of solution. This is known as a scaling condition. Conversely, water with low levels of hardness will produce an aggressive condition. In aggressive conditions (soft water), the water will take the calcium it wants directly out of your plaster, resulting in plaster breakdown and bond failure. See similar questions...

Woods range in hardness and density. Various tests can be and have been done to test for these characteristics. Traditionally, a harder wood was used in the public spaces such as living and eating rooms, while softer woods could be used in more private spaces such as upstairs bedrooms. Antique woods will be harder and denser than their modern counterparts, due to the slow growth nature of forests that were harvested over one hundred years ago. Floor hardness is a matter of aesthetic choice. See similar questions...