… disc‑sealed (lighthouse) tubes, stabilising valves, thyratrons, ignitrons, etc. The heading includes : (1) … and in general have two electrodes. Certain types (e.g., thyratrons) have control grids so that their operation can …
… metal). In the case of castors having pneumatic tyres, the diameter of the castor must be measured with the tyre inflated to a normal pressure. The presence of …
… manufacture of iron, copper, nickel and their alloys), in pyrotechnics, etc. The pure metal has poor mechanical … of powders and flakes. These products are used in pyrotechnics (fire‑works, signals, etc.), as reducing agents …
