Conversion FactorsTech Tip #30 2000

MassMultiply to get Apoth dram Apoth dram Apoth dram Apoth dram Apoth lb Apoth lb Apoth lb Apoth lb Apoth oz Apoth oz Apoth oz Apoth oz Avdp drams Avdp drams Avdp drams Avdp drams Avdp lb Avdp lb Avdp lb Avdp oz Avdp oz Avdp oz carats carats grams grams lb oz 60 0.1371 0.008571 3.88794 5760 13.1657 0.822857 373.242 480 1.09714 0.068571 31.1035 27.344 0.0625 0.003906 1.77185 7000 16 453.592 437.5 0.0625 28.3495 3.0865 0.2 15.432 0.0353 0.4536 28.35 to get Divide grains Avdp oz Avdp lb grams grains Avdp oz Avdp lb grams grains Avdp oz Avdp lb grams grains Avdp oz Avdp lb grams grains Avdp oz grams grains Avdp lb grams grains grams grains oz kg grams

Pressure/VacuumMultiply to get atm atm atm atm atm atm bar bar bar ft H2O kPa kPa kPa psi 33.9 760 1033.2 14.70 1.013 101.3 14.5 0.9869 100 0.4335 0.01 0.1450 7.5 0.0703 to get Divide ft H2O mm Hg g/cm2 psi bar kPa psi atm kPa psi dyne/cm2 psi mm Hg kg/cm2

LengthMultiply to get inch ft ft yard Angstrom 2.54 12 0.305 1.094 1010 to get Divide cm inch meter meter meter

FlowrateMultiply to get cc/min cfm (ft3/min) cfm (ft3/min) cfh (ft3/hr) cfh (ft3/hr) GPH GPH GPM GPM oz/min 1 28.31 1.699 472 0.125 63.1 0.134 0.227 3.785 29.57 to get Divide mL/min L/min m3/hr mL/min GPM mL/min cfh m3/hr L/min mL/min

MiscellaneousMultiply to get hp hp hp hp watts watts lb-ft oz-in oz-in oz-in gauss 0.746 42.44 396,000 1.014 0.7376 44.25 0.1368 0.072 70,600 0.00706 0.0001 to get Divide kW Btu/min lb in/min metric hp lb ft/sec lb ft/min kg-m kg-cm dyne-cm Nm tesla

VolumeMultiply to get cubic cm (cc) oz (fluid) cubic ft (ft3) cubic ft (ft3) gal gal gal cubic meters 1 29.57 7.48 0.0283 128 3.785 0.8333 1000 to get Divide mL mL gal m3 oz (fluid) liters imp gal liters

EquationsCentrifugal ForceRelative centrifugal force rcf = (11.18 x 10-6) RN R = rotating radius in cm N = rotation speed in rpm

FlowCv factor CQ=v

(G/P)

1

2

Heating and CoolingCooling capacity of chillers Btu/hr = T (F) x Specific heat of fluid flow rate (GPM) Specific heat of water = 500 Btu/hr/GPM/F Specific heat of oil = 350 Btu/hr/GPM/F Heating water in tanks kW = Volume (gallons) x T (F) 325 x Heat-up time (hours) Heating oil in tanks kW = Volume (gallons) x T (F) 800 x Heat-up time (hours) Heating flowing water kW = Flow (GPM) x T (F) x 0.16

ConcentrationMolar (M) = Moles of solute Liters of solution Weight % = Grams of solute x 100% Grams of solute + grams of solvent Volume % = Liters of solute x 100% Liters of solution ppm = mg of solute = mg kg of solution Liters of water

Q = CV = G = P =

flow rate (GPM) flow coefficient specific gravity pressure drop (psi)

Density ConversionsSpecific Gravity x 1 = g/L g/L x 8.345404 = lb/gal lb/gal x 0.119826 = g/mL

TemperatureF = (1.8 x C) + 32 C = (F 32) x 0.555 Kelvin = C + 273.2

Tech Tip #30 page 2

HumidityAbsolute humidity (as g/m3) D= 804 x e 1 + 0.00633t PO = H x 804 x e 100 1 + 0.00366t POrelative humidity (% RH) standard air pressure (mm Hg) absolute humidity (g/m3) water steam pressure (mm Hg) absolute humidity in saturation (g/m3) eS = saturated water steam pressure (mm Hg) t = temperature (C) T = dew point temperature H= PO = D= e= DS =

Ohms lawVoltsVolts = Watts x Ohms Volts = Watts Amperes Volts = Amperes x Ohms

AmperesAmperes = Volts Ohms

W I IR E I

WR E R(VOLTS) (OHMS)

W E W R EI I R2

Amperes = Watts Volts Amperes = Watts Ohms

E

OhmsOhms = Volts Amperes2

(AMPS) (WATTS)

I

RW 2 I E W2

WE R2

WattsWatts = Volts x Amperes Watts = Amperes2 x Ohms 2 Watts = Volts Ohms

Ohms = Volts Watts Ohms = Watts 2 Amperes

Dew point temperature (as C) T = 237.3/7.5 - 1 log e 0.786 e= H xe 100 S eS = 6.1078 x 107.5t/(237.3 + t) Relative humidity (as % RH) RH = e x 100 = D x 100 eS DS

Electrical DiagramsAC SWITCH (SPST) SWITCH (DPST)

current loopAC SWITCH (SPDT) 4-20 mA controloutput control output AC power SWITCH (DPDT)

4-20 mA

4-20 mA output

Conversion TablesImportant Metric PrefixesPrefix teragiga-* megakilodecicentimillimicronano-* pico-* Abbreviation T G M k d c m n p Meaning x 1012 x 109 x 106 x 103 x 101 x 102 x 103 x 106 x 109 x 1012

Conductivity Values /cm at 77F (25C)% Weight 0.0001 0.0003 0.001 0.003 0.01 0.03 0.1 0.3 1.0 3.0 5.0 10.0 20.0 30.0 40.0 50.0 75.0 100.0 ppm mg/l 1 3 10 30 100 300 1000 3000 10,000 NaCl 2.2 6.5 21.4 64 210 617 1990 5690 17,600 48,600 78,300 140,000 226,000 Saturated Saturated Saturated Saturated Saturated NaOH 6.2 18.4 61.1 182 603 1780 5820 16,900 53,200 144,000 223,000 358,000 414,000 292,000 191,000 150,000 Saturated Saturated HCl 11.7 35.0 116 340 1140 3390 11,100 32,200 103,000 283,000 432,000 709,000 850,000 732,000 Saturated Saturated Saturated Saturated Acetic acid 4.2 7.4 15.5 30.6 63 114 209 368 640 1120 1230 1530 1600 1405 1080 740 168