Min. cutting height
The minimum cutting height provided by the lawnmower — that is, the smallest height of grass that can remain after the passage of the machine. It makes sense to pay attention to this indicator mainly in cases where the lawn is planned to be cut as short as possible. In addition, the lower the minimum height (with the same maximum), the wider the height adjustment range of this model.
Deck material
The material from which the deck is made is a protective casing that covers the cutting tool of a lawn mower or trimmer. In modern mowers there are such options:
— Plastic. The cheapest and at the same time the least durable material.
— Aluminium alloy. The most advanced option: these decks are durable, lightweight and less prone to corrosion, but quite expensive.
— Steel. It has greater strength than aluminium alloy and costs less, but is heavier and more prone to corrosion.
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.