Panametrics 5222 Ultrasonic Gauge is a handheld thickness‑measurement instrument featuring a digital display, velocity counter and XDCR port. Common failures include an open‑circuit or depleted lead‑acid battery that will not charge, resulting in no power to the probe driver; degraded ultrasonic transducer or XPCR probe causing unstable readings; and internal logic board faults that can manifest as erratic display values or loss of signal. First‑check diagnostics: verify 6 V battery voltage and replace if below 5.5 V; inspect the XPCR probe for physical damage or loose connections; and confirm the gauge’s internal power supply and driver ICs by checking output voltages to the transducer circuit.[oss-gpt-20b]