The sensing element of the instrument is an electrochemical cell. The cell is a four-electrode type, which contains a working and an active auxiliary electrode. The signal from the auxiliary electrode is used for temperature compensation and to improve the selectivity of the entire sensor. The sensor response is linear with the concentration of the target gas in air.

The Z-700XP meter stores all of the exposure points for up to 5 logs (a log is created in the instrument's internal memory each time it is used). A log contains: date, time, number of exposure points, the interval between each point, and the actual exposure points. All of the log files can be easily uploaded to PC using components vailable within the Microsoft Windows Operation System or the termianl software included with the instrument.