Knick’s Portavo 904 (X) line of portable meters for pH values, conductivity, and oxygen feature an ATEX approval for zones 0 and 1, thereby allowing users to monitor process measuring points in hazardous areas. They support digital Memosens sensors as well as analog pH and conductivity sensors. Portavo meters meet the requirements of on-site and laboratory operation: their housings are made from a high-tensile polymer. Thanks to IP66/IP67 protection, they are suitable for use in rugged industrial environments. The integrated protective cover protects the display from scratches and damages, and also serves as benchtop stand. Additionally, the housings feature an integrated quiver that prevents the sensor from drying out. The new MemoLog function saves the calibration data of all Memosens measuring points and makes them available for the analysis of the sensor parameters. Data can be easily transferred to a PC via the integrated USB interface. The Paraly SW 112 software, which is included in delivery, allows users to easily store, display, document, print, and process measured values, calibration protocols, and calibration data.