The inlet is baffled to prevent sunlight from entering and raising the background noise in the detector. The target was planned to be a corrugated Ag or other heavy metal material. It was not necessary to have a moving Ag foil for the Wild flyby, as was done for the higher flux at Halley. The target area was increased to 50 cm2 from the Halley Mission instrument's 5 cm2 target. During its operation, a light flash, which accompanies the dust impact on the target, is detected and used to set the zero for the TOF measurement.
Electrostatic grids extract ions, depending from the impact microplasma.
These ions move down a bent-tube TOF MS, with an electrostatic reflector to focus ions of similar energies onto the ion detector. By measuring their arrival time, the mass of the ions can be determined. The use of a recorder mode allow a superior data set to be collected, than what was possible from the data-constrained links that were available during previous PIA flights. Most of this data will be played back slowly over ensuing days or weeks after the comet flyby. The Finnish Meterological Institute is developing software for the CIDA instrument.