Volume; Mass Per Unit Volume Of Water; Specific Heat; Temperature - Honeywell AUTOMATIC CONTROL Engineering Manual

VOLUME

Cubic
inches
3
Existing Unit (in. )
Cubic inches —
3
(in. )
3
Cubic feet (ft ) 1728
Cubic centimeters 0.06102 0.0000353
3
(cm )
Gallons, US 231
(US gal)
Gallons, Imp 277.42
(Imp gal)
Liters (L) 61.024
Ounces, fluid 1.805
(oz fluid)
Quarts, 57.75
(qt liquid)
Cubic meters 6 1024
3
(m )
EXAMPLE:
64 gallons (US) x 3.7854 = 242.27 liter s

MASS PER UNIT VOLUME OF WATER

62.383 lb/ft 3 or 8.343 lb/gal
0.999 kg/l or 9.99 g/cm 3

SPECIFIC HEAT

Specific heat of water = 1
Specific heat of steam (water vapor) = 0.49
Specific heat of air = 0.24
The specific heat of water is the reference for all other
substances and means that one Btu will change the temperature
of one pound of water one degree Fahrenheit. If a substance
has a specific heat of 0.25, then 1/4 Btu will change the
temperature of the substance one degree Fahrenheit or one Btu
will change the temperature of that substance four degrees
Fahrenheit.
Similarly 4.7 kJ will change the temperature of one kilogram
of water one kelvin. If a substance has a specific heat of 0.25,
then 4.7 kJ will change the temperature of that substance four
kelvins.
EXAMPLE:
1 gpm w ater a t 20F ∆T = 10 000 Btuh
1 L/s water a t 10 kelvins = 1692 kJ per hour
Table 9. Volume Conversion Multipliers.
Cubic
Cubic centimeters
3 3
feet (ft ) (cm )
0.0005787 16.387 0.004329
— 2832 7.481
— 0.0002642 0.00022
0.13368 3785.4
0.16054 4546 1.2009
0.03531 1 000 0.2642
0.001044 29.58 0.007813
0.03342 946.4 0.25
35.31 1 000 000 264.2
Desired Unit
Gallons, Gallons,
US Imp Liters
(US gal) (Imp gal) (L)
0.003605 0.016387
6.229 28.32
0.001
— 0.8327 3.7854
— 4.546
0.22 —
0.0065 0.02957
0.2082 0.9463
220 1 000

TEMPERATURE

Most temperature conversions will be between Fahrenheit
and Celsius (Centigrade) scales. These cannot be done with a
simple multiplier. The formulas are:
Temperature in degrees F = 9/5 x degrees C + 32.
Temperature in degrees C = 5/9 x (degrees F – 32).
Since Fahrenheit and Celsius scales coincide at –40 the
following alternate formulas may be used:
Temperature in degrees F = 9/5 x (degrees C + 40) – 40.
Temperature in degrees C = 5/9 x (degrees F + 40) – 40.
NOTE: A temperature range or span does not require
the factors to adjust the zero reference of the
temperature scales. A range or span is denoted
as Degrees Fahrenheit or Degrees Kelvin (K)
and converted as follows:
Degrees F = 9/5 x degrees K
Degrees K = 5/9 x degrees F
Absolute zero is noted in degrees Rankine (R) or Kelvin.
The approximate conversions are:
Degrees R = degrees F + 460.
Degrees K = degrees C + 273.
477 ENGINEERING MANUAL OF AUTOMATIC CONTROL
GENERAL ENGINEERING DATA
Ounces, Quarts,
fluid liquid
(oz fluid) (qt liquid
0.5541 0.0173 0.0000164
957.5 29.92 0.002832
0.0338 0.01057 0.000001
128 4 0.003785
153.7 4.803 0.004546
33.818 1.0568 0.001
— 0.03125 0.0000296
32 — 0.0009463
33 814 1056.7
Cubic
meters
3
(m )
—