Monitoring for shielding-gas applications
In order to help simplify the work of quality managers in companies with gas systems, Witt (Witten, Germany) has updated its range of analysers, introducing the new PA 7.0 to the market: a completely redesigned instrument for measuring the concentration of oxygen and carbon dioxide.
The new PA 7.0 is used, for example, in the food industry for the analysis of shielding gases and can accomplish two tasks at once: in addition to the continuous, in-line monitoring of gas mixtures, the instrument can take random samples using a sampling needle, e.g. for checking modified atmosphere food packaging. A further advantage is that minimal sample gas is required. According to the manufacturer, the instrument only requires about 3 ml of sample gas for reliable analysis, depending on the application. The measuring cells (chemical, zirconium and infrared) work from 0 to 100 percent.
For the PA 7.0, practically all features and capabilities of the series-6 predecessor model have been further developed and improved. The hygienic stainless-steel housing has been redesigned and is ideally suited to meet the demands of industrial applications. The USB port and SD card slot for data transmission and updates are located on the front of the instrument for easy accessibility. Sufficient connections are available for communication with other instruments and optimal integration into existing systems (e.g. digital inputs and outputs, 24 V inputs and outputs, relays).
Limit values are set individually by the user; if one of these values is reached, the PA will emit an alarm or switch a potential-free contact, for example, to interrupt the gas supply. The flow is monitored continuously using modern electronics and pressure transmitters, while the pump output is varied in accordance with requirements. The PA is even able to detect a needle blockage, in which case it signals an alarm.