That’s the stability indicator . Green = stable reading. Red = fluctuating field. The manual suggests waiting for a green light before recording data.
: Depending on the complexity of the device, users may require training to operate it effectively and safely. simco fmx002 manual top
: 0 to ±1.49 kV (Low range); ±1.0 kV to ±20.0 kV (High range). That’s the stability indicator
The FMX-002 typically operates in two modes depending on the charge level: Measures up to ±1.49kV with high resolution. simco fmx002 manual top