Comparison TFA Multy vs TFA 35.1102

The types of meteorological information and related data that the device can provide.

— Weather forecast. The weather station can estimate forecasts based on data from its sensors, considering factors like temperature, humidity, and wind. The accuracy of these forecasts varies across models and tends to be relatively low, providing only a rough idea of potential changes. Typically, weather data is presented with symbolic images depicting sun, clouds, rain, etc., and forecast periods extend to about 12–24 hours. Despite limited precision, this feature proves valuable for taking precautionary measures in anticipation of adverse weather. It's essential to note that markings such as "Rain," "Variable," "Clear," etc., on mechanical barometer scales in certain models (see "Mechanism"), are not considered weather forecasts as they are highly subjective.

— Internal temperature. The weather station includes an internal thermometer for measuring room temperature where the main unit is placed. This feature proves especially useful for managing microclimates, particularly in critical environments like greenhouses. Internal thermometers typically have a narrower operating range but higher accuracy compared to external ones. They are a standard feature in most modern weather stations across various types (see "Mechanism"), except for specialized professional models exclusively designed for outdoor o...bservations. Portable devices (see "Installation") are not explicitly designed for this function, although they can be used indoors; their primary purpose remains outdoor use, and the built-in temperature sensors align with that purpose.

— Outside temperature. The possibility of using a weather station to measure the air temperature outdoors. Usually, an external temperature sensor is performed separately from the main unit; the only exceptions are portable devices (see "Installation"). Separately, we note that it is not necessary to carry out such measurements using an “internal” thermometer (see above): outdoor work requires a wider temperature range, and the device must also be protected from dust and moisture.

— Internal humidity. The weather station offers the capability to measure indoor air's relative humidity, a crucial factor in determining comfort within a room. Maintaining the right humidity level is essential, as both excessively dry and overly humid air can lead to discomfort. This feature is particularly valuable for specific purposes, such as regulating microclimates in greenhouses or incubators.

— External humidity. The weather station is equipped to measure outdoor air's relative humidity, typically using an external sensor for this purpose (excluding tourist models). It is strongly advised not to substitute an internal sensor for accurate readings. This parameter is crucial for weather forecasting and assessing overall comfort conditions. High humidity intensifies the perception of both cold and heat, significantly influencing comfort levels (see below).

— Atmospheric pressure. The weather station is capable of providing data on atmospheric pressure, a crucial factor for weather forecasting. Unlike temperature and humidity measurements, pressure readings are not categorized into internal and external, as the pressure in an unpressurized room typically aligns closely with external conditions. While an internal barometric sensor suffices for accuracy, some models include a barometric sensor in the external unit for enhanced precision. It's important to note that the "atmospheric pressure" function is specific to devices capable of outputting detailed pressure data, and not all barometric sensor-equipped models provide this feature — some only indicate pressure increase or decrease.

— Wind speed and direction. The weather station is equipped to measure wind speed and direction, contributing to enhanced weather forecasting accuracy (both by the station and through independent calculations). These measurements also impact the outdoor comfort level display. Typically, a sensor combining a weather vane and an anemometer is employed for this purpose, and this feature is prevalent in advanced weather stations.

— Precipitation level. The weather station can measure precipitation levels, although specific details about rain or snow are seldom necessary in everyday life. A casual glance out the window is usually enough for a general assessment of conditions. However, for the meticulous recording of weather observations and scientific analysis of weather data, precise information about precipitation becomes crucial. As such, this function is predominantly found in professional weather stations.

— Dew point. The weather station can calculate the dew point, which is the temperature at which air moisture cools and condenses into dew. This parameter, influenced by atmospheric pressure, temperature, and relative humidity, provides a reliable indicator of overall comfort conditions for individuals. Dew points of 10–12 °C are considered most comfortable, lower values can cause dryness, 18 °C is seen as the comfort limit, while conditions with a dew point of 26 °C or higher can pose health risks, especially for respiratory conditions. The dew point is also relevant for technical purposes, and further details on its significance for human well-being and various activities can be explored in specialized sources.

— UV radiation. The possibility of using a weather station to measure the intensity of ultraviolet radiation. This function is important primarily for beaches and high-mountain areas — it is for such places that an increased level of ultraviolet radiation is characteristic, which requires appropriate protective equipment (creams for open skin areas, special glasses).

— Altimeter. The weather station can measure elevation differences, a feature commonly found in tourist-oriented models (see "Installation"). Other types are generally stationary and not designed for mobility. Altitude measurement typically follows the barometric principle, relying on pressure differences between a reference point and the measurement point. In advanced models, corrections for temperature differences between these points may also be available.

The type depends primarily on the method of connecting an external sensor to the main unit of the weather station.

— Wired. Sensors with such a connection are not as convenient as wireless ones (see below): the wire limits the mobility, can create inconvenience, and its laying can be associated with certain difficulties — for example, a opening in a wall, window frame or other similar place is required to lead outside. On the other hand, this option is cheaper, while providing better and more interference-resistant communication — if there is enough wire, the sensor will be guaranteed to work. In addition, such equipment does not require autonomous power supply, which makes it more reliable in terms of resistance to bad weather.

— Wireless. Sensors that communicate with the main unit via radio. This option is extremely convenient to connect: you do not need to pull the wire through walls and other obstacles for connecting. However, the range of radio communication is noticeably reduced in the presence of obstacles (see below for more details), and the channel is subject to electromagnetic interference; but the power of modern transmitters is usually enough for reliable operation within even a large private house, and modern technologies provide more than sufficient noise immunity. But of the significant shortcomings, it is worth noting the increased sensitivity to bad weather, especially low temperatures. This is due to the fact that wireless sensors n...eed their own power sources, and most modern batteries and batteries do not tolerate frost well. In addition, such equipment is much more expensive than wired equipment, all other things being equal.

— Number of sensors. The total number of sensors that can be linked to the weather station and send measurements to it. The presence of several sensors allows you to determine the weather conditions in different areas: these can be different rooms of the same building or different parts of the world. The location of the sensors relative to the structure can significantly change the accounts, therefore, to achieve more reliable results, 2 or more remote sensors are usually provided.

The maximum distance to the main unit of the weather station where an external sensor can be placed. For wired versions (see "Type of external sensor") this indicator corresponds to the length of the standard cable; for wireless, a guaranteed radio communication range is usually indicated within the visibility limit, provided there is no interference or foreign objects in the signal path. Anyway, it should be taken into account that the maximum installation range is usually less than the claimed range in fact. This is due to the fact that the wire can rarely be laid in a straight line, and the radio signal, in turn, is affected by obstacles and electromagnetic interference. Therefore, it is worth choosing a weather station for this parameter with a certain margin.

The temperature range at which the weather station's internal temperature sensor (see "Measurements") can operate normally. Of course, for normal use, it is need to the temperatures in the room do not go beyond the specified range — otherwise the device will give a warning about the impossibility of measurements in the best case, and at worst it will fail altogether. However, it should be noted here that temperature fluctuations inside residential and office buildings are relatively small, and even in the most inexpensive weather stations, the operating range of the corresponding sensors covers these fluctuations with an impressive margin. Therefore, it makes sense to pay close attention to the measurement temperature in the room only when the device is purchased for non-standard applications — for example, for installation in a greenhouse or in a warehouse with low temperatures.

The temperature range for which the external temperature sensor of the weather station is designed (see "Measurements"). This parameter must correspond to the temperature differences that this sensor may be exposed to during operation — otherwise, malfunctions and even hardware failures are possible. Of course, it is worth choosing a model according to external temperature, taking into account the climate in which it is planned to be used; at the same time, it is worth taking a certain margin both in the lower and in the upper side. The last is connected not only with the possibility of climatic fluctuations, but also with the fact that outdoor equipment can be heated from direct or reflected sunlight; this, of course, must be avoided in every possible way, but it is not always possible to find an perfect fitting location for the sensor.

— Display of the temperature trend. This "weather forecast" relies on recent temperature measurements. A decline in parameters suggests an impending cold spell, while an increase indicates imminent warming. The function predicts whether temperatures will rise or fall in the very near future.

— Backlight display. The display of the weather station incorporates a backlight feature, enabling information readability in low-light to complete darkness. While this consumes energy, it is particularly relevant for self-powered models. However, since the backlight is typically used for only a few seconds, the associated additional costs are minimal. The backlight may come in various colors and, in some instances, serves decorative purposes.

— Clock. The weather station includes its own clock, initially displaying the current time. However, the clock's data can be used for additional functions like recording temperature extremes and operating an alarm clock. Clocks can be electronic or analog, typically aligning with the weather station's mechanism type. Some models even offer the option to synchronize time precisely through radio signals.

— Alarm clock. The weather station features an alarm clock function, emitting a sound signal at a user-set time. Beyond waking up, this signal can serve various purposes, such as event alerts or task reminders. As alarms inherently require a clock (see a...bove), the available signals vary among models — ranging from a standard sound to multiple options. Advanced models may even permit users to download custom sound files (see "Connecting to a PC").

— Calendar. Availability of a calendar function in the weather station. The simplest option involves at least displaying the current date and day of the week, advanced features may include viewing a calendar table for a month or even a year. The calendar can be used not only by itself, but also for other functions — primarily informing about sunset/sunrise (see above).

— Moon calendar. The presence in the weather station of a calendar that displays the phases of the moon. This information can be used for a variety of purposes, from monitoring tides to finding the best time for gardening or beauty/medical treatments. The moon calendar is usually combined with the usual one (see above).

— FM receiver. The weather station includes an FM-range receiver, enhancing the user experience with access to a variety of stereo music stations. However, it's important to note that FM broadcasting has a limited range, typically within line of sight (a few kilometers). This function may be less useful in remote areas far from cities. Optimal reception requires an external antenna, which can be a traditional telescopic antenna or the wire of an external sensor or headphones.

— Photo frame. The weather station has the capability to function as a digital photo frame, allowing users to view photos on its high-quality color display or run a slideshow for aesthetic appeal. While the display quality contributes to the cost, this feature is primarily aesthetic, as viewing photos is often more convenient on dedicated devices like smartphones or tablets. As a result, this function hasn't gained widespread popularity.

— Projector. The weather station features a built-in projector, enabling the display of various data (weather, time, etc.) on walls, ceilings, or other surfaces, essentially transforming them into impromptu displays. This projection method can be more convenient than viewing information on the main device display in certain situations. However, such models tend to be expensive. The projector typically takes the form of a rotary unit, allowing optimal adjustment of the projected "picture" position.

This concerns how the transmitter in the external sensor of a weather station is powered, specifically for wireless sensor models. Wired sensors, as mentioned earlier, don't have transmitters; they derive the required energy for operation through a wired connection.

The majority of models use sensors powered by standard-sized, replaceable batteries — either disposable or rechargeable cells. This choice is driven by considerations of battery life and the convenience of swiftly swapping out depleted batteries without removing the entire sensor. While this method incurs additional costs for separate battery purchases — either ongoing expenses for disposables or a relatively higher upfront cost for rechargeables—these drawbacks are generally deemed non-critical. Overall, the advantages of this approach outweigh these concerns for several reasons.

Dimensions of the main unit of the weather station. This option allows you to estimate the space required to install the device. However, most modern models are very compact, it makes sense to pay close attention to the dimensions only when you have to install the device in a very cramped place.