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.
Number of height settings
The number of cutting height settings provided by the lawn mower. The more such settings (with the same adjustment range) — the more accurately you can choose the mowing height. Note that in some robots (see "Type") this number reaches 30 or more with a range of 30 to 60 mm; in other words, you can select the height to the nearest millimetre.
Recommended area
The area of the site for which the lawn mower is designed. It cannot be argued that this parameter is critical when choosing a device, these are only manufacturer's recommendations and are very conditional. However, they are more than justified and generally show the available front of work based on the heating of the motor, the capacity of the tank or battery, and other factors that affect the duration of work.
Grass ejection
Direction of ejection of grass cut by the lawnmower.
The main options for the direction of ejection are back or sideways; there are also models in which you can choose the direction. At the same time, we note that in classic units, the ejection back is almost always carried out
into the bag(up to the point that when the bag is removed, the hole is automatically covered with a lid), but when the bag is ejected from the
side, it may not be — this is convenient, for example, when mulching ( see above).
Also note that riders (see "Type") have their own specifics: in units with rear discharge, after removing the bag, it is necessary to install a special plug, and then the cut grass will simply remain under the deck. In some
mini-tractors, a similar way of working (without a bag) is provided initially; it is also considered a rear ejection, although the grass does not flow backwards, but downwards.
Front wheel diameter
The diameter of the front wheels of the unit. For more information about this parameter, see "Rear wheel diameter" — everything written there is true in this case. We only note that the front wheels relatively rarely have their own drive, so the diameter for them is not as important as for the rear ones.
Rear wheel diameter
The diameter of the rear wheels of the unit.
Larger wheels, on the one hand, increase cross-country ability and allow you to effectively overcome pits, bumps and other obstacles on rough terrain. On the other hand, they cost more, are more expensive, and in self-propelled models, they also require more traction from the engine.
This indicator is often determined by the type of lawn mower (see above). So, mowers and riders, by definition, have large wheels, because they are designed for difficult terrain, and in a minitractor, the wheels must also withstand a fairly significant weight. But
robotic lawn mowers, on the contrary, are used mainly on flat surfaces with low grass, and they do not need large wheels.
If you have to choose among classic lawn mowers, where this parameter can be different, you should proceed from the planned working conditions. So, if we are talking about a flat lawn — you can not pay much attention to this indicator; but for rough terrain with pits, tubercles, ditches, etc., you should choose larger wheels — from 25 cm or more.
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.