Standards determine slope and offset before any unknown is inverted. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

The first standard pair fixes slope and offset

Standards (0, 4) and (4, 12) give slope 2 and offset 4.

m=2,b=4m=2,\quad b=4
Calibration lineStandards fix slope, offset, inverse value, and range gate.low standardhigh standard

A shifted standard pair can give a smaller offset

Standards (1, 3) and (5, 11) still give slope 2, but offset 1.

m=2,b=1m=2,\quad b=1
Calibration lineStandards fix slope, offset, inverse value, and range gate.low standardhigh standard

A steeper standard pair changes the line identity

The third row uses standards (0, 3) and (3, 12), giving slope 3 and offset 3.

m=3,b=3m=3,\quad b=3
Calibration lineStandards fix slope, offset, inverse value, and range gate.low standardhigh standard