De Dietrich 97957093 ionisation probe

This ionisation probe, listed under De Dietrich as part number 97957093 / 336.946.044, belongs to the category of ionisation electrodes used for flame detection in gas-fired burners. Parts of this type serve to prove the presence of a flame by conducting a small rectified current through the ionised gases of the flame. The probe is mounted so that its tip sits directly in the flame zone, typically on the main burner or on a pilot burner. The signal from the ionisation electrode is sent to the burner control (flame safeguard), which must detect a stable flame current within the safety time after fuel admission; otherwise the control locks out. Ionisation probes are consumable components because their tips are exposed to high temperature and corrosive combustion products. When replacing a probe of this type, the selection must match the original in electrode length and bend, insulator diameter, the electrode gap (distance to ground), and the mounting flange design. The probe must also be compatible with the specific burner series for which it was shaped, since the position and curvature of the electrode determine its position relative to the flame. Typical failure modes include an eroded or oxidised tip, a cracked ceramic insulator, soot deposits that insulate the electrode, or a drift in the electrode gap that lengthens or prevents reliable ignition. Any of these conditions can cause a loss of flame signal or intermittent lockout, so regular inspection is recommended during annual servicing. No specific dimensions, voltage ratings, or compatible burner models can be stated for this article beyond the manufacturer codes given; the heating engineer should verify the physical fit and electrical connection against the existing part before ordering.