How to Measure Length

Because measurements using a meter stick are straightforward, no explanation is provided. There are, however, two possible complications when using a meter stick. One problem is reading beyond the limits of the measurement device, and the other is parallax (see Fig. 2.1, Fig. 2.2, and Fig. 2.3). 

Meter sticks have major limitations in that they can only measure flat objects. For example, it is impossible to accurately measure the outside diameter of a round-bottom flask, the inside diameter of an Erlenmeyer flask neck, or the depth of a test tube with a meter stick. Fortunately, there are various devices and tech- 

Once depth is established with a depth gauge, measurement can be read directly, or the device is removed and laid onto a meter stick to determine depth measurement. 

The ends of a pair of dividers can be inserted into an object to obtain an internal measurement. The dividers are then removed and laid on a meter stick to obtain the measurement. 

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