Additional nozzle
The width of the additional nozzle provided with the device.
Additional attachments are mainly supplied with window models (see "Type"). Such a nozzle is usually made narrower than the main one — it makes it easier to work on small glasses and in hard-to-reach places. However, there is also the opposite option: a small capture width in the device itself, increased by using an additional nozzle.
Detergent tank
The volume of the cleaning solution tank installed in the cleaning machine.
This parameter is directly related to the device type (see above) and some features of its functionality. So, in powerful self-propelled scrubbers (see "Type") tanks with a volume of tens of litres can be provided, while in floor cleaning robots the capacity does not exceed 1 litre (and in some models, it is only 120 mL). So, according to this spec, only units of the same type with similar functionality can be compared with this parameter. With such a comparison, it is worth proceeding from the fact that a more capacious tank, on the one hand, allows you to work longer without refuelling; on the other hand, it affects the dimensions and weight.
Waste detergent tank
The volume of the waste solution tank installed in the harvester.
Such tanks are equipped exclusively with floor scrubbers (including household ones) and window models (see "Type"): we recall that both of them are designed for suction of the solution from the treated surface. In general, the larger the tank, the less often it will have to be emptied, but the larger the dimensions and weight of the unit. Therefore, manufacturers usually choose this indicator taking into account the type and characteristics of the application of the machine. So, in devices for windows, which are held in the hands during operation, the capacity of the tanks for the spent solution is small — usually about 150 – 200 mL; this is quite enough, taking into account the format of application, and at the same time, such additional weight does not create inconvenience during work. In turn, scrubbing machines use containers of several liters or even tens of liters; usually, a specific volume directly depends on the overall “weight category” and the performance of the machine.
Voltage
The voltage of the battery used in the machine with the appropriate type of power supply. This parameter is not a key one when choosing: it may be needed only when looking for a third-party charger or a replacement/spare battery, as well as for specific calculations related to capacity (see below).
Autonomy time
The operating time of a battery-powered cleaning machine on a single charge of a standard battery.
By itself, this parameter is quite approximate: it is most often indicated for standard operation and simple conditions. However, the actual battery life usually does not differ much from the indicated one. So, according to the claimed autonomy time, it is quite possible to evaluate the capabilities of different models and compare them with each other.
Charging time
The time required to fully charge the battery of cleaning machine (see "Power supply").
The larger the battery, the longer it may take to charge it. On the other hand, this moment also depends on the type of battery. In addition, special technologies are being used to speed up the process. So two machines with a similar battery capacity can differ in charging times.
Noise level
The noise level generated by the cleaning machine during operation.
A low noise level is important for the comfort of the operator and the people around. The latter is especially true in some specific places like hospitals or kindergartens. On the other hand, the higher the power, the louder, usually, the unit operates and the more difficult it is to reduce this noise to a certain level, even though in many cases the high volume of the work is not a particular problem. So it’s worth looking specifically for a “quiet” cleaning machine only if a low noise level is more critical for you than a high cost and/or reduced power.
When evaluating specific loudness values, note that the decibel used to indicate the noise level is a non-linear value. Therefore, it is easiest to evaluate specific values using comparative tables. Here is a simplified table for the range that most modern cleaning machines fit into:
55 dB — background sound in the office without special noise sources;
60 dB — loud conversation;
65 dB — city street with average traffic intensity;
70 dB — a conversation of several people in raised tones.
75 dB — high-power vacuum cleaner.
80 dB — traffic noise on a busy street.
Weight
The total weight of the cleaning machine. Usually, weight is indicated with empty tanks for detergent, waste, fuel, etc. At the same time, additional equipment, such as side brushes, may or may not be taken into account. Such equipment has a very small weight compared to the machines themselves. And, when installed/removed, does not seriously affect the mass of the entire machine.
