I hope it can help you out as well .

**

Psig to Psia = Psig + 14.7

Psia to PSig = Psia - 14.7

**

.491 = density of 1 cu" Hg

**

29.921 "Hg = perfect vacuum

**

pressure = Height * density

**

Density = Weight / volume

**

absolute pressure = gauge + atmospheric

gauge + ( Barometer "Hg * .491 )

**

absolute pressure = (Barometer "Hg - Vacuum gauge "Hg) * .491

**

1 PSIG =

2.307 ' WC

27.68 " WC

2.036 "Hg

**

1 ' WC =

12" WC

.433 psig

15.133 psia

.8826 "Hg

**

1 "Hg =

13.6" WC

1.133 ' WC

.4912 psig

15.1912 psia

**

1 atmosphere =

33.96 ' WC

14.7 psig

1 psia

760 mm Hg

29.912 "Hg

**

1 Cu ' =

1728 Cu "

(H2o) 62.4 lbs

7.48 gal

**

1 Gal =

231 Cu "

8.33 lbs

**

H20 specific gravity = 1.0

**

Specific gravity = weight cu ' / 62.4

**

Rankine - Kelvin - Fahrenheit - Celsius

R to F = R + 460[*] ( 459.67 ) [*] book states this

K to C = K + 273[*] ( 274.15 ) [*] book states this

F to R = F - 460

C to F = C - 273

R to C = R - 492 / 1.8 ( or R - 492 * .555 )

K to F = K - 273 * 1.8 + 32

R to K = R - 492 / 1.8 + 273

K to R = K - 273 * 1.8 + 492

F to C = F - 32 / 1.8 ( or F - 32 * .555 )

C to F = C * 1.8 + 32

**

BTU = amount of heat to raise 1 LB water 1F

calorie = amount of heat to raise 1 gr water 1C

**

1 BTU = 252 calories

1 calorie = .00397 BTU

1 kilo calorie = 3.97 BTU

**

1 ton refrigeration ( 1 ton ice melted over 24 hours ) = 288,000 BTU or 12,000 BTU hour

**

Convert 1 LB ice @ 32F to water, requires 144 BTU latent heat

**

time response measured in time constants - up to 5

**

x = 0

y = 0

~time constant 1 = pressure rise total * .632 + original pressure

x = pressure rise total * .632

Y = X + original pressure

~ time constant 2 = X * .632 + y

X = X * .632

Y = Y + X

~ time constant 3 = X * .632 + y

X = X * .632

Y = Y + X

~ time constant 4 = X * .632 + y

X = X * .632

Y = Y + X

~ time constant 5 = X * .632 + y

[ note: this is in programming terms so I can understand it - it's more confusing in the book ]

**

span = subtracting lowest range value from highest range value.

conversion of signals = find span of input and output - find the percentage of the (current input value - low value) compared to the

input span. Use that percentage on the output span. Add the low value from the output range

IE:

Input = Temperature range 100F - 500F

Output = Pressure range 3 psig - 15 psig

Current temperature = 300F

Input range = 400

Output range 12 psig

--

current temperature - low range = 200F

200 / 400 = .50 ... .50 * 12 psig = 6 psig .... 6 psig + 3 psig = 9 psig output signal

**

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