GB/T 7274-2015Methods for the measurement of direct inter-electrode capacitances of electronic tubes and valves (English PDF)

3.1 Coupling capacitor

In composite pipe and twin tube, while the other element electrode and the reference ground, the other electrode group with one of the electrodes in one electrode group

A capacitance between the electrodes.

4.1

electrode capacitance test should be carried out in GB/T 2421.1-2008 test prescribed in 5.3 standard atmospheric conditions.

4.2

electrode capacitance relative error test shall meet the following requirements.

A) when the test is less than 0.001pF capacitor, the relative error of the test. 20% to 20%;

b) Test 0.001pF ~ 0.1pF capacitor, the relative error test. ~ 10% -10%;

C) When the test is greater than 0.1pF capacitor test relative error. -5% to 5%.

4.3

Unless otherwise specified, the capacitance between the electrodes should be in addition to the voltage test tube capacitance required, the voltage is not applied to any other situation

Under the conditions tested.

Under the 4.4 capacitance should be directly tested, it should not be used in combination of two or more independent tests determined capacitance. When testing, in addition to the measured power

Other than the capacity of the electrode poles are connected to a reference point and the reference point of the circuit should not be confused with application of the ground.

4.5

All types of electrode capacitance test tube, if there are several hot wire or electrode lead, the lead pipes should be connected in a corresponding seat together. Within two or more connected components, should be regarded as a member. For example. in the gate and the cathode is connected, it should be regarded as a cathode.

4.6

Test tube inter-electrode capacitance, can be used to test tube socket, pipe caps, wire, shield or adapters and other special shape of the tube may not be […]