Comparison Vitals BK 552s Black Edition vs Vitals Master BK 3109-4a

The capture width provided by the unit, in other words, the width of the strip of land cultivated in one pass. In fact, this size corresponds to the width of the working nozzle.

The large working width is useful when processing large open spaces, as it allows you to finish the job in a small number of passes. On the other hand, for hard-to-reach places, relatively narrow tools are better suited, able to go where a wider unit will not fit. In addition, the width of the tool directly affects the weight and price.

In general, it makes sense to compare in terms of working width only units of the same type (see above). However, it is worth noting here that trimmers do not differ so much from each other — most models capture from 25 to 45 cm (and a wide processing band is provided by moving the nozzle from side to side). As for the other types, in the most modest models the capture width does not exceed 40 cm, in the heaviest and most powerful it can be 56 – 60 cm or even more(in mini tractors — up to 1.5 m).

The width (diameter) of the trimmer knife characterizes the size of the paddle knife (or saw blade). Such a nozzle has a smaller capture width than a fishing line, however, it allows you to mow more dense thickets, including shrubs.

Scheme of operation of an internal combustion engine installed on a lawn mower. Note that this division is relevant only for gasoline engines (see "Engine type") — diesel engines are extremely rare and are made only four-stroke.

— 2-stroke. The main advantages of two-stroke engines over four-stroke ones are the simplicity of the device and higher power with the same working volume, due to which such units are lighter, more compact and cheaper. On the other hand, they consume more fuel and are distinguished by a high level of noise, and such an engine needs to be filled with a mixture of gasoline and oil in the correct proportion, which complicates maintenance somewhat (there are separate refueling systems, but they are complex and expensive, which is why they are almost never used ). As a result, this option is found mainly among trimmers (see "Type"): it is there that small dimensions and weight are decisive, and the required power and fuel consumption are relatively low.

— 4-stroke. Engines of this type are somewhat more complicated and more expensive than two-stroke ones; in addition, to achieve the same power, they need more volume, which affects the size and weight. On the other hand, if the engine does not need to be "carried in the hands" (as is the case with trimmers), these points do not really matter; and the difference in price, thanks to the development of technology, is becoming less and less noticeable. Wit...h all this, four-stroke engines are quieter and consume less fuel. As a result, almost all units where a relatively large and heavy internal combustion engine can be installed are equipped with this particular type of engine. And relatively recently, light and compact engines have appeared, suitable even for trimmers.

The size of the engine installed in the petrol or diesel model (see "Engine type"). Power directly depends on this indicator, however, only engines of the same type can be compared by volume (see "Type of internal combustion engine"). And even in the same type of units of the same power, the volume can be different. In such cases, note that a larger volume means more fuel consumption, but the engine itself may cost less than a smaller one.

Lawnmower engine power expressed in horsepower. The common unit of power these days is the watt, but gasoline and diesel engines (see "Engine Type") are traditionally referred to as hp. Some units are easy to convert to others: 1 hp. approximately equal to 735 watts.

In general, the more powerful the engine, the more performant the mower is and the better it handles with heavy work such as cutting thick grass, bushes, etc. On the other hand, high power has a corresponding effect on fuel consumption, as well as the weight and price of the engine. In addition, it should be taken into account that different types of mowers (see "Type") differ in terms of power requirements. For example, among trimmers there are many models with a capacity of 0.7 – 1.3 hp., for gasoline lawn mowers, the minimum power is already in the range of 1.3 – 2 hp., and for mowers, at least 2.5 hp is required. . So you can only compare units of the same type in terms of power. Detailed recommendations for choosing a mower depending on its type and features of the planned work can be found in special sources.

Lawnmower engine power expressed in watts. This designation is used absolutely for all electric models (see "Engine type"), and it is also often found in gasoline and diesel units along with horsepower (these units are clearly related, 1 hp is about 735 watts).

In general, the more powerful the engine, the more performant the mower and the better it will cope with heavy work such as cutting thick grass, bushes, etc. On the other hand, high power has a corresponding effect on fuel / electricity consumption, as well as the weight and price of the engine. In addition, note that the power requirements depend on the type of mower itself and its engine (see above for both). For example, for most robots, the power does not exceed 500 W — more, taking into account specialization, is not required, besides, otherwise the devices would turn out to be too bulky and heavy. Trimmers and lawn mowers of similar power are only electric, and the power limit for power tools is 2500 – 3000 W when powered from the mains and 1500 – 2000 W for battery models. But in gasoline tools, the minimum power is about 500 – 1000 W for trimmers and 1000 – 1500 W for mowers; the maximum value can exceed 4 kW.

Detailed recommendations for ch...oosing a lawn mower depending on its type and features of the planned work can be found in special sources.

The volume of the fuel tank in a gasoline or diesel mower (see "Engine type").

A large tank allows you to work longer without refueling, but an excessive increase in capacity affects the dimensions and weight of the entire unit. So manufacturers usually select this indicator taking into account the power and fuel consumption of a particular engine, and in general, the volume of the tank is not critical when choosing. However, knowing the tank capacity and fuel consumption (see above), you can estimate how much one refueling will approximately last.

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.