Click

A click may contain a number of impulses; in which case the relevant time is that from the beginning of the first to the end of the last impulse.

Switching operation: One opening or one closing of a switch or contact.

7.4.2 Discontinuous disturbance

7.4.2.1 The minimum observation time T is obtained at both measuring frequencies (150 kHz and 500 kHz) in the following way:

For appliances which stop automatically, the shorter time of either:

1. the time to register 40 clicks, or, where relevant, 40 switching operations, or
2. 120 min. (2 hr)

For appliances which stop automatically, the duration of the minimum number of complete programs necessary to produce 40 clicks or, where relevant, 40 switching operations. When, 120 minutes after the beginning of the test, 40 clicks have not been produced, the test is stopped at the end of the program in progress.

The interval between the end of one program and the start of the next program shall be excluded from the minimum observation time, except for those appliances for which an immediate re-start is inhibited. For these appliances, the minimum time required to re-start the program shall be included in the minimum observation time.

7.4.2.2 The click rate N shall be determined under the operating conditions specified in 7.2 and 7.3 or, when not specified, under the most onerous conditions of typical use (maximum click rate) at 150 kHz for the frequency range 148.5 kHz to 500 kHz ant at 500 kHz for the frequency range 500 kHz to 30 MHz.

The receiver attenuator is to be set such that an input signal equal in amplitude to the relevant limit L for continuous disturbance produces a mid-scale deflection on the meter.

7.4.2.3 The click rate N is obtained in the following way:

In general N is the number of clicks per minute determined from the formula N=n1/T, n1 is the number of clicks during the observation time T minutes.

For certain appliances the click rate N is determined from the formula N=n2*f/T where n2 is the number of switching operations during the observation time T and f is a factor given in annex A, table A.2.

7.4.2.4 The relevant click limit Lq for discontinuous disturbance is determined in accordance with the formula given in 4.2.2.2. (The click limit Lq is the relevant limit L for continuous disturbance, as given in 4.1.1, increased by 44 dB for N<0.2, or 20 lg (30/N) dB for 0.2<=N<30.)

Limit L for household appliances and equipment causing similar disturbances
and regulating controls incorporating semiconductor devices at mains terminals

If the click rate N is determined from the number of switching operations, the appliance under test shall be deemed to comply with the limit if not more than a quarter of the number of switching operations registered during the observation time T produce clicks exceeding the click limit Lq.