A functional check uses a simulated oily water fluid which causes the measuring cell to activate a high PPM alarm. It will demonstrate correct operation of the measuring cell, alarms and 3-way valve on board. It is ideal for demonstrating correct operation to an inspector. IT DOES NOT constitute a calibration as the instrument is not being adjusted with a reference sample. Any functional check or calibration check certificate issued by an attending company DOES NOT satisfy IMO requirements for calibration. A calibration requires a calibrated sample fluid and reference cell. OEM and Dealer only software allows adjustment of the vessel measuring cell to match the reference cell value. A calibration certificate is issued by the OEM / Agent to confirm this has been completed.