Max. cutting height
The maximum cutting height that the lawn mower can achieve is the maximum height of grass that can be left after the machine has passed.
This parameter is relevant mainly for those cases when you want to leave the grass on the lawn relatively long. In addition,
lawn mowers with high cutting heights have a wide range of mowing adjustments.
Revolutions (electric motors)
The maximum speed that the engine in an electric mower can run at (see "Engine type").
It makes sense to compare according to this indicator only engines of the same power. In general, higher rpm improves performance but reduces torque. Conversely, a relatively slow engine will be inferior to a “fast” one in overall speed, but it will better cope with dense dense vegetation. So it’s worth choosing by engine speed, taking into account what is more important to you — speed or efficiency in difficult conditions.
Noise level
The level of noise produced by the device during operation. Usually, a certain average indicator is indicated in the characteristics — in the standard mode of operation; however, the actual values usually do not differ much from the claimed ones.
The lower the noise level, the more convenient the unit to use and the less tired the operator. In the case of lawn mowers, this is especially true, since such equipment is quite noisy — even the quietest models (some robots) give out about 47 – 48 dB, which is comparable to talking at an average volume. Note that the decibel is a non-linear quantity, and it is easiest to evaluate the actual loudness using comparative tables. Here is the simplest table for the values found in modern lawn mowers:
— 60 – 65 dB — talking in raised tones at a distance of about 1 m;
70 dB — loud conversation of several people at the same distance;
75 dB — loud laughter at a distance of 1 m;
80 dB — motorcycle engine, medium power vacuum cleaner.
90 dB — loud screams, freight car at a distance of 7 – 10 m;
100 dB — a subway train or a loud car signal at a distance of 5 – 7 m, an industrial workshop;
110 dB — tractor engine at a distance of about 1 m.
In addition to subjective sensations, there are specific sanitary standards that limit the impact of strong noise. So, according to European standards, noise of 85 dB is allowed to be heard without protective equipment for 8 hours, 91 dB — 2 hours, 97...dB — half an hour, and 103 dB — only 7 minutes. So when choosing a unit, you should take into account the duration of work with it — with high noise, you may need protective headphones.
