Basic Units of Measurement and Conversions - Basic Mathematics for Water and Wastewater Operators - page 63

TABLE 2.7 (continued)
Conversion Factors by Unit Category

Factor Metric (SI) or English Conversions

1 psi (pounds per square inch) 0.068 atm (atmosphere)

27.67 inch H 2 O (inches of water)
68.85 mb (millibars)
51.71 mmHg (millimeters of mercury)
6894.76 Pa (pascals)

1 torr 1.33 mb (millibars)

Units of Velocity or Speed

1 fps (foot per second) 1.097 kmph (kilometers/hour)

0.305 mps (meters/second)
0.01136 mph (miles/hour)

1 mps (meters per second) 196.9 fpm (feet/minute)

3.6 kmph (kilometers/hour)
2.237 mph (miles/hour)

1 mph (miles per hour) 88 fpm (feet/minute)

1.61 kmph (kilometers/hour)
0.447 mps (meters/second)

Units of Density

1 g/cm 3 (grams per cubic centimeter) 62.43 lb/ft 3 (pounds/cubic foot)

0.0361 lb/in. 3 (pound/cubic inch)
8.345 lb/gal (pounds/gallon)

1 lb/ft 3 (pounds/cubic foot) 16.02 g/L (grams/liter)

1 lb/in. 2 (pounds/cubic inch) 27.68 g/cm 3 (grams/cubic centimeter)

1.728 lb/ft 3 (pounds/cubic foot)

Units of Concentration

1 ppm (parts/million-volume) 1.00 mL/m 3 (milliliter/cubic meter)

1 ppm (wt) 1.00 mg/kg (milligram/kilogram)

Radiation and Dose Related Units

1 Bq (becquerel) 1 radioactive disintegration/second

2.7 × 10 -11 Ci (curie)
2.7 × 10 -8 (millicurie)

1 Ci (curie)

3.7 × 10 10 radioactive disintegrations/second
3.7 × 10 10 Bq (becquerels)
1000 mCi (millicuries)

1 Gy (gray) 1 J/kg (joule/kilogram)

100 rad
1 Sv, unless modified through division by an
appropriate factor, such as Q or N