1.12 Summation of Error

When there are 2 or more quantity where each of them have limiting error combined through an equation. This combination normally involving addition, subtraction, multiplication and division operations. The result is described in a (𝑦±𝛿𝑦) or (𝑦±𝛿𝑦𝑦) form.It can be assumed as an error caused by two or more reading value which have their own error, combined in a worst case.

A and B = the value of instrument A and B

ΔA and ΔB = the absolute error for A and B

%A and %B = limiting error for A and B

So,the unit and error is;
1) A= A +ΔA
2) A= A + %A
3) B=B + ΔB
4) B=B + %B