ID-8

Pressure measurement principle of the ID-8 transmitter

The ID-8 works on an inductive principle. Pressure from the working medium acts on the internal diaphragm, and diaphragm movement changes the inductive balance of the coils inside the unit. The connected cockpit indicator reads this electrical change and moves the pointer on the scale. This type of transmitter requires the correct aircraft AC supply, so it cannot be checked properly as a simple passive sensor. During troubleshooting, maintenance personnel normally verify the pressure line, transmitter response, wiring continuity, connector condition and indicator compatibility before replacing the unit.

ID-8 in Mi-8 and Mi-17 engine oil systems

The ID-8 is often used in helicopter engine oil pressure indication systems, including Mi-8 and Mi-17 applications with TV2-117 or TV3-117 engine installations, depending on the aircraft configuration. In this role, the transmitter is fitted in the engine oil system and sends pressure data to cockpit instruments such as UI-series indicators or DIM-type pressure indication equipment. The transmitter may be mounted on an engine accessory unit, oil manifold, filter housing or connected pressure line. The exact position should always be checked against the engine and airframe documentation.

Gearbox and air system use of ID-8

Apart from engine oil systems, the ID-8 can be used in gearbox oil pressure monitoring and in selected air system circuits. On Mi-8 type helicopters, one common system area is the main gearbox oil circuit, where pressure indication helps the crew monitor lubrication of the transmission. The transmitter may also be used where air pressure needs to be monitored in service lines, for example in systems connected with oil seal pressurization or other pneumatic functions. The working medium and installation point depend on the aircraft variant and the system drawing.

Connected instruments around the ID-8 sensor

The ID-8 normally works with cockpit pressure indicators such as UI-1, UI-2, UI1-8 or DIM-8, depending on the aircraft equipment set. It is part of a measuring chain: pressure source, threaded installation point, transmitter, aircraft wiring, power supply and cockpit gauge. A mismatch between the transmitter range and the indicator scale will give incorrect indication even if both parts are serviceable. For replacement work, the transmitter should be selected together with the installed indicator type and the measured system, not only by visual similarity.

Identification and ordering of ID-8

Before ordering ID-8, the marking should be compared with the aircraft parts catalog, engine documentation or gearbox system diagram. It is useful to confirm the measured medium, installation point, required pressure range and compatible cockpit indicator. On aircraft that have passed through overhaul, the actual installed indicator or wiring may differ from the original configuration. A photo of the transmitter label and connector helps avoid mistakes. The product is also known under alternative designations ID-8, ID8, ID-8 and ID8.