The FS620 is used to monitor the flow status of solid particles in flexible hoses. When the flow rate exceeds the set threshold, the device sends a signal via relay output. Versions with an analog output (4…20 mA) can also further indicate flow trend variations. During the conveying of granules, powders, blasting media, dust, or other solid materials, such as in pneumatic conveying systems, the device can detect abnormal conditions in real time and with high reliability, including pipe blockages, empty hoppers, or bridging at the bottom of storage silos.