Square root tolerance for calibration calculations

The square root calculation is used to perform the input limits and output tolerance calculations for differential pressure producing flow meters.

Square root calculations

You select the Square Root of Input check box to use this calculation.

The formula for calculating the desired output is included in the square root equations.

The following figure shows the desired output calculation:
Figure 1. Desired output calculation
Desired output calculation
Table 1 shows the positive square root equation and negative square root equation for each criterion.
Table 1. Single square root equations for input
Criterion Description Positive square root equations Negative square root equations

EU

When the Square Root of Input check box is selected, the positive square root equation is used for the engineering unit criterion.

The negative square root equation is used if the input + tolerance is a negative number.

EU single positive square root equation
EU single negative square root equation

%Span

When the Square Root of Input check box is selected, the positive square root equation is used for the %Span criterion.

The negative square root equation is used if the input + tolerance is a negative number.

%span single positive square root equation
%Span single negative square root equation

%URV

When the Square Root of Input check box is selected, the positive square root equation is used for the %URV criterion.

The negative square root equation is used if the input + tolerance is a negative number.

%URV single positive square root equation
%URV single negative square root equation

%Reading

When the Square Root of Input check box is selected, the positive square equation is used for the %Reading criterion.

The negative square root equation is used if the input + tolerance is a negative number.

%Reading single positive square root equation
%Reading single negative square root equation

Table 2 shows the positive square root equation and negative square root equation for a summed square root.

Table 2. Summed square root equations for input
Description Summed square root equation

Positive square root equations

Summed positive square root equation

Negative square root equations

Summed negative square root equation