Sentence:  The strength of the acid can be determined by the use of an <WSD>acidometer</WSD> and a glass cylinder. The <WSD>acidometer</WSD> is placed in the cylinder and sufficient acid at 60°F. is then added to make the <WSD>acidometer</WSD> float. 
Meaning of the word marked with <WSD> tags:  A hydrometer, especially one that is used to measure the strength of an acid.