# Calibration of Weight using the ABBA Method

In this article, you will learn the calibration procedure of weight using the ABBA method.

Where A is Standard Weight and B is UUC weight (UUC is Unit Under Calibration)

Select an appropriate standard weight for calibration of UUC Weights.

i.e one class higher standard weight is required for UUC weight Calibration.

For F1 class calibration of weights, E2 class weight is required as standard weight

## Calibration of Weight using the ABBA Method

1. Keep Standard weight A on weighing Balance and note down the reading.
2. Keep UUC Weight B on weighing Balance and note down the reading. Remove weight from the weighing balance.
3. Again, Keep UUC Weight B on weighing Balance and note down the reading.
4.  Keep Standard weight A on weighing Balance and note down the reading.

This completes one set of reading.

ABA Method and AB1…..BnA are similar Methods.

ABBA          Standard   ______ UUC  ______ UUC  ______ Standard

ABA             Standard ______  UUC  ______ Standard

AB1…..BnA   Standard  ______  UUC ______ UUC  ______  UUC (n times) ______ Standard

The equation for Determination of Conventional Mass

mct = mcr(1+C)+Δmw

Where

mct is the Conventional mass of test weight

mcr is the Conventional mass of reference weight

C is the Buoyancy correction factor

Δmw is the difference in weight by the ABBA method

For the same material weight with the same density, the Buoyancy correction factor is Zero.

ΔM is calculated as follows for ABBA Method

Let’s consider ABBA as A1B1B2A2

ΔM = [(B1-A1) +(B2-A2)] /2

A1 = first reading of reference weight

B1 = first reading of test weight

B2 = second reading of test weight

A2 = second reading of reference weight