A 35-item, seven-point Likert-like scale is used to measure the clarity of mental images a person is able to evoke. This measures a person's general ability to imagine several types of sensations and is not limited to a particular sense or stimulus. It has been referred to by various names, but most of them include the original creator's name (Betts).
As a researcher, it's important to use validated scales to ensure reliability and improve interpretation of research results. The Marketing Scales database provides an easy, unified source to find and reference scales, including information on reliability and validity.