order

04:03 Jan 16, 2017 

Виноват, в оригинале все же есть порядковые спектры в виде ordering spectra. Это в последнем абзаце раздела 4.6:
The other advantage is that it is possible to obtain averaged records with the rotational angle a “time‑axis” now, and also in the case of non‑steady rotational frequency, and then to process ordering spectra for only the vibration at orders of the r/min. If vector averages are used, vibration at other frequencies will not have a constant phase with respect to the r/min, and will average to zero. Ordering spectra can be averaged without any smearing of the components.

03:55 Jan 16, 2017 

Order tracking was first done with a tracking filter for alias protection, and a ratio synthesizer to change the r/min signal to a sampling frequency (2,56 times the highest order of interest). Noise and accuracy concerns, along with restrictions on the rates of change in r/min, led to computed order tracking, which digitizes the process.

In computed order tracking, both the vibration signal and the r/min signal are digitized with fixed sampling rates. The r/min signal is used to establish the sampling rate for each revolution, and the vibration signal is interpolated and re‑sampled at the appropriate intervals for the order analysis to establish a stepwise changing individual sampling frequency for each revolution or, by means of polynomial interpolation, a continuously changing sampling frequency can also be generated.

As indicated in 4.3.8, this process has two additional advantages over time‑based sampling. All the energy for each order is in the middle of the window for each bin, eliminating the error caused by not being in the middle, which can be up to 15 %.

03:53 Jan 16, 2017 

Раз в этом ГОСТе Order tracking из оригинального стандарта ИСО переведено как порядковый анализ, логично использовать порядковый спектр. С другой стороны, order в этом стандарте переведено как гармоника, а вот порядкового спектра (order spectrum) в оригинале вообще нет, это издержки перевода.
Вот первый абзац раздела 4.6 из стандарта ISO 13373:2-2016:
4.6 Order tracking (analogue and digital)
When obtaining frequency spectra from machines, if the rotational speed of the machine varies, it can be difficult to obtain meaningful averages because the energy from a particular order can be reflected in more than one frequency bin, and at lower levels than if the speed were constant. By controlling the sampling rate according to the speed of the machine by means of external sampling (see 4.3.8), all of the energy in a particular order of vibration will be reflected in just one frequency bin. This is normally accomplished by using a once‑per‑revolution signal as input to a dynamic signal analyzer and is called order tracking.

20:15 Jan 15, 2017 

Похоже, что это все-таки порядковый спектр:
http://docs.nevacert.ru/files/gost/gost_r_iso_13373-2-2009.p...
п. 4.6