Portable instruments are tools designed for easy transport and use in various settings. They are often lightweight and compact, making them ideal for fieldwork, travel, or home use. Examples include digital multimeters, handheld spectrometers, and portable oscilloscopes, which allow users to measure and analyze different physical properties without needing a fixed laboratory. These instruments are essential in many fields, such as engineering, environmental science, and medicine. For instance, a portable ultrasound machine enables doctors to perform quick assessments in remote locations. Their versatility and convenience make portable instruments invaluable for professionals and hobbyists alike.