Confirm that the ground terminal is grounded (100 Ω or less).
The ground terminal is used to obtain the reference potential for neutralization, so if it is not grounded, the discharge amount of the emitter may become unstable and the number of ions generated may decrease. In addition, even when the main unit power is ON without air purge, the discharge of the electrode needle may become

When the female threads for piping type is selected , the pressure inside the nozzle of the main body increases due to the shape of the piping nozzle. When the pressure rises, the ion generation rate decreases.
Because of this, sometimes the maintenance warning turns ON and the NDL LED lights up.
When attaching one of SMC’s various special order nozzles or piping prepared by the customer