Comparison UNI-T UT300S vs UNI-T UT306A

The design determines the overall shape of the hull.

— Pistol. This option assumes the presence of a pistol grip located at an angle to the body. The handle allows you to comfortably hold the device during operation.

— Direct. Straight body without any curved handles. This design is used relatively rarely — mainly among compact devices, where the manufacturer sacrifices the handle for the sake of reducing dimensions. Paying attention to this variety is worth it if you are looking for a small, most convenient device to carry.

The range of surface temperatures that the instrument can effectively measure.

In general, the meaning of this parameter is quite obvious. We only note that an extensive operating range is not always an advantage. First, it affects the cost of the device; secondly, when the range is extended, the measurement accuracy may deteriorate. So when choosing, you should not chase the maximum temperature range, but take into account real needs: for example, it hardly makes sense to choose a pyrometer with an upper limit of 500 °C for measuring the quality of thermal insulation and determining heat leaks in residential premises. It is conditionally possible to divide pyrometers into those that are for measuring low temperatures, and, accordingly, for high ones.

Instrument sighting index.

The sighting indicator is the ratio between the distance to the surface, the temperature of which is measured, and the diameter of the spot that enters the field of view of the device. For example, if at a distance of 2 m the device will cover a zone of 10 cm (0.1 m), then the sighting index will be 2 / 0.1 = 20.

When choosing for this parameter, it is worth considering the expected measurement conditions — the dimensions of the objects whose temperature is supposed to be measured, and the distances to them. At the same time, it is worth remembering that for accurate measurement, the measured surface must completely occupy the field of view of the pyrometer — otherwise the device will also “see” foreign objects, the radiation of which will distort the measurement results. Therefore, for long distances, models with high sighting rates are recommended — 40, 50, etc. If measurements are planned to be carried out at a distance of one or two metres, and the measured objects are quite large, you should pay attention to models with relatively small values of this parameter — 10 , 20 etc.

Approximate response time of the device, namely the time that elapses from pressing the measurement button until the results are shown on the display (or from a change in temperature to a change in the readings on the display, if we are talking about continuous measurement mode). In most cases, this parameter does not play a special role: even in the "slowest" devices, it does not exceed 1000 ms (1 s), which does not lead to any inconvenience. It is worth paying attention to the response time only if the device is planned to be used to measure the temperature of fast moving objects: the faster the reaction, the less time you have to keep the measured object in the field of view of the pyrometer, the lower the likelihood that this object can “jump out” from the field of view until the end of measurements.

The range of ambient air temperatures over which the instrument can perform its functions normally.

All modern pyrometers are guaranteed to work at room temperature. At the same time, they usually allow deviations from it within 15 – 20 °C — for example, in many models, the operating temperature range is claimed within 0 ... 40 °C. So you should pay attention to this indicator if the device is planned to be used at temperatures below zero, or vice versa, in hot conditions — not every model is able to work normally with one or another “extreme”.

Note that going beyond the range of permissible temperatures does not necessarily lead to a breakdown of the device. However, one should not deviate from these recommendations, at least in the light of the fact that under abnormal conditions the device begins to give too high an error, and there is no need to talk about any measurement accuracy.

— Adjustment of emissivity. The ability to adjust the device to the emissivity of different materials. The emissivity determines how much energy a given surface radiates at a certain temperature; it is expressed by numbers from 0 to 1 (coefficient 1 has an perfect “absolutely black body”). Without going into too much physical detail, we can say that if the instrument settings do not correspond to the actual emissivity of the surface being measured, the measurement results will also differ from the actual temperature. However, most of the surfaces that one has to deal with in fact — wood, brickwork, plastic, coated with paint and metal oxides — have an emissivity of 0.8 – 0.9; pyrometers are set to these indicators by default, and additional correction during measurements is generally not required. But the radiation index of polished metal and some other materials can be noticeably lower than these values, and the pyrometer must be adjusted separately for such surfaces. Well, anyway, if the maximum accuracy of measurements is critical for you, you should choose a device with adjustable emissivity and adjust it for each individual surface. There are special tables that allow you to determine this coefficient for different types of materials.

— Backlight. The presence in the device of its own backlight. In this case, both conventional and ultraviolet illumination can be implied. The fir...st actually complements the pyrometer with a flashlight function and makes it easier to work in low light conditions. UV illumination, on the other hand, is primarily designed to detect refrigerant leaks in air conditioners and refrigeration units: many refrigerants contain an additive that glows in UV rays. The specific type of backlight for each model should be specified separately.

— USB port. Standard USB connector for connecting the device to a computer, laptop, etc. Usually, to use the possibilities of such a connection, you need to install special software from the manufacturer's website. Connectivity may vary. So, the recording function is often encountered when the computer constantly monitors the readings of the device, building a chart or table of temperature fluctuations. Other devices may provide the ability to copy measurements from their own memory to a PC. The USB port can also be used to charge the battery (see "Power") and configure the pyrometer — for example, adjusting the emissivity (see above), calibrating, updating the firmware, etc. The specific set of capabilities in each case should be clarified separately.

— RS-232. Also known as a COM port. Service connector for connecting the pyrometer to computers and some types of specialized equipment. Data can be transmitted via RS-232 in two directions: an external device can record pyrometer readings and, if necessary, control instrument settings from it.

— Bluetooth. Bluetooth wireless technology is used for direct connection between different devices. Theoretically, the ways of using such a compound can be different; Specifically, in this case, Bluetooth is mainly used to connect the pyrometer to a smartphone, tablet or gadget and transfer measurement results to this gadget. To process the results, usually, you need to install a special application; it provides a variety of additional capabilities and is often more convenient than manual processing of results, especially when dealing with large amounts of data.

- "6LR61". A standard 9-volt Krona battery is rectangular in shape, with a pair of contacts at one end. Quite a popular option: for a number of reasons, 9 V voltage is very convenient for use in pyrometers.

—AA. A popular standard size of replaceable cells is known as “pen-cell batteries”. Similar elements are also available in the form of rechargeable batteries. In pyrometers, such power supply is less common than “Kronas” - in particular, because several AA batteries are usually required for effective operation. However, this is also a fairly popular option.

- AAA. Another common standard size of replaceable elements is “pinky batteries”. Similar to the AA described above in everything, with the exception of a smaller size and, accordingly, lower capacity. They are used mainly in compact devices, for which even AA batteries are too bulky.

— Branded battery. Powered by its own battery of the original standard, which can also be made non-removable. On the one hand, such power has a number of advantages over replaceable batteries. Thus, the battery is initially included in the kit, it does not need to be purchased separately; and when the charge is exhausted, there is no need to spend money on fresh batteries - just leave the device to charge. On the other hand, charging requi...res a power source and takes quite a long time, while batteries, if there are spare ones, can be changed in a matter of seconds. Therefore, this option was not particularly widespread.

- CR2032. Quite miniature “tablet” batteries with a diameter of 32 mm and a thickness of 2 mm. Due to their low capacity, they are used extremely rarely - exclusively in miniature devices designed for maximum compactness and, as a rule, intended for short distances (up to 1 m).

There are also models with combined power supply that can operate from one or another source.

— “Krona” / external power supply. Models capable of operating both from the Krona battery described above and from the supplied AC power supply. The advantage of this option is that if there is an outlet, the device can be connected to it, saving battery power (or even charging it if a battery in the “Krona” form factor is used for power).

— AA / branded battery. Devices that can operate both from replaceable AA batteries and from a branded battery. To do this, the package usually includes an adapter that allows you to install a set of batteries instead of the battery. Note that the battery itself is not necessarily supplied with the pyrometer - on the contrary, batteries may be included in the package, but the battery must be purchased separately (or removed from another instrument of the same brand - some manufacturers use universal interchangeable batteries for their devices). See above for more details on each type of power supply, and their combination gives the user a choice and, in theory, allows them to mutually compensate for deficiencies. On the other hand, in most cases it is easier to buy replacement elements in the form of batteries than to mess with a branded battery, so this option is not particularly widespread.

The maximum operating time of the pyrometer on one battery or accumulator charge (see "Power").

In general, the meaning of this parameter is quite obvious, it is worth noting only one nuance: different brands of replaceable batteries can vary significantly in capacity. Therefore, when using inexpensive elements, the actual operating time of the pyrometer may be significantly less than the claimed one.