... , wine, sugar, beverages, etc. Level Control level difference can be set directly for various tank liquid level measurementwith RS232 or RS485 ... ,5,6,8,10Mdisplay resolution: d = 1mm/1cm to be set during calibration stageshows: 4 digit and 8 segment 0.39 ... data output keyboard: four water proof touch keys which can set top/bottom level, TTL level output (optional) .Working frequency: 38500 ~ 43000 HZ ...