1. Read the pressure in inches of water from the pressure gauge. Interpolate as necessary on an analog gauge. 2. Use a calculator for speed and accuracy. Enter the pressure reading
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You need to multiply by 0.036. So 5 x 0.036=18 psi.
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I am going to send you a link to help better explain it
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27.68 inches of water is equivalent to one pound per square inch of pressure. So, take your value of inches of water use the conversion factor to cancel your units to psi. For example
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