Comparison Suunto Smart Sensor vs Beurer PM 200+

— External. An external chest sensor is directly attached to the chest using a special belt, typically communicating wirelessly with the main unit. This communication can be through a universal interface like Wi-Fi or Bluetooth, a specialized one such as ANT +, or even a distinct natural frequency. This design ensures accurate measurements, allows flexibility in fastening the main unit of the heart rate monitor, and minimizes inconvenience. The sensors don't restrict movements much and have lenient requirements for dimensions and weight, contributing to cost-effectiveness. As a result, chest sensors are widely popular.

— Built-in. Built-in sensors refer to sensors installed directly in the main unit of the heart rate monitor, consistently in contact with the skin. This design is convenient as everything needed is housed in a single unit, reducing the risk of losing the sensor. They offer continuous heart rate monitoring, but the options for fastening are limited (see "Purpose"), typically restricted to the wrist due to the need for constant skin contact. Strict requirements for dimensions, weight, and the design's complexity impact the cost, and measurement accuracy is generally lower. Due to these factors, built-in sensors are not widely adopted.

— Finger sensor. A finger sensor reads heart rate data from the fingertip, typically the index finger. In...some wrist-mounted models, these sensors are integrated into the case, requiring touch for pulse measurement. Unlike built-in sensors, finger sensors don't provide continuous monitoring but offer higher accuracy. Another option is a clip-like "clothespin" attached to the fingertip, akin to sensors in medical equipment. While these allow constant pulse monitoring, they are less convenient for vigorous activity and are uncommon.

— Ear clip. Another type of "clothespin," in this case designed for attachment to the earlobe. These clips are smaller and less restrictive than finger clips, making them more suitable for active activities. However, achieving light and compact sensors with wireless connections is challenging, and additional wires can make the structure unwieldy. As a result, ear clips are uncommon, primarily found in neck-mounted models (see "Purpose").

Measurements and calculations that can be carried out with the device.

— Heart rate. Heart rate measurement in real-time is a crucial feature for devices with a heart rate monitor function and is primarily the main function for heart sensors and pulse oximeters. In fitness, heart rate is a key parameter, aligning with various training goals such as fat burning, maintaining shape, or cardiovascular strengthening. Many models can also detect critical situations like heart rhythm disturbances or excessive heart rate, providing user warnings. However, it's important to note that not all heart rate monitors or combined devices offer continuous monitoring; some models require touching the sensor for measurements. Therefore, for constant pulse data, ensure the selected device supports continuous monitoring.

— The level of oxygen in the blood. The pulse oximeter function measures blood oxygen saturation levels using a specialized sensor in a non-invasive manner, without puncturing or damaging the skin. It's important to acknowledge that the oxygen level sensor is not a certified medical device. However, it effectively responds to critical decreases in saturation, such as those experienced by climbers at high altitudes or individuals with specific respiratory conditions.

— Perfusion Index (PI). A parameter found exclusi...vely in pulse oximeters (see “Type”). Perfusion Index (PI) is a measure of blood flow in the finger being measured. The PI indicator is measured as a percentage and can vary from 0.3 to 20%. A value in the range of 4 – 7% is considered normal. If you deviate from this range, the saturation measurement results may be distorted.

— Number of steps. Step count measures the number of individual steps taken by the user, aiding in achieving recommended activity levels for a healthy lifestyle, fitness, or physical therapy. The function calculates steps taken in various ways, such as recording results for multiple sessions or days, displaying total and average numbers, remembering target values, and signaling their achievement. It's important to note that not all devices with a pedometer function (refer to "Type") support step count measurements. Some devices, designed for professional sports where movement speed is crucial, may prioritize other metrics over step count.

— Distance travelled. The function measures the total distance covered by the user. Basic models calculate distance in real-time, while more advanced ones can summarize results and work with target values. There are two main measurement methods: classic pedometers determine distance by multiplying the number of steps by the set step length (refer to "Individual settings"), while models with GPS use satellite navigation data (see "Features"). The first method has a larger error, but it's often not critical. The second method is more accurate but is costlier and may not work well in areas with weak satellite signals, such as dense urban areas or indoors.

— Movement speed. Measurement of the current movement speed. Like the distance traveled, this indicator can be calculated in two ways — by the number of steps or by data from the GPS module; see above for details on both methods. The simplest measurement option provides measuring the speed only at the current time, however, additional features may be provided — for example, building a schedule for a workout.

— Energy expenditure (calories). The function measures the amount of energy expended during a workout, commonly referred to as "burned calories". Monitoring energy consumption is crucial in weight management training programs as it helps track metabolism. However, it's essential to note that modern heart rate monitors and pedometers do not directly determine actual energy consumption. Instead, they estimate the number of calories based on factors such as heart rate, movement speed, number of steps, user's personal characteristics (refer to "Individual settings"), and other indirect parameters. Despite being approximate, these calculations are generally accurate enough for practical application.

— The amount of burning fat. The function calculates the amount of burned fat during a workout, typically measured in weight units such as grams. Similar to energy consumption, the device doesn't directly measure the actual fat burned but estimates it from various auxiliary data. The accuracy of these measurements is relatively low, and this parameter is not a primary focus in fitness. However, tracking the amount of fat eliminated can serve as additional motivation for users.

— Average/maximum heart rate. Calculation of the average and maximum value of the heart rate for a certain period of time (usually for one training session). These calculations are based on general information about the heart rate; about its meaning, see above.

— Activity time. The function measures the total duration of the user's physical activity, specifically recording only the time during which the device sensors detect the activity. Breaks in sessions are excluded from the recorded time. For instance, if you walked 1000 steps in 20 minutes with a 3-minute break, the recorded activity time would be 17 minutes. This feature distinguishes it from a regular stopwatch (refer to "Features") and enables accurate tracking of the duration and intensity of training loads.

Data transfer standards supported by the device.

— Wi-Fi. Originally designed for computer networks and internet access, Wi-Fi is now commonly used for direct communication between devices, notably in fitness devices. While internet connectivity is possible, it's typically for specific tasks like firmware updates or saving data to network storage. The prevalent Wi-Fi version, 802.11n, theoretically offers a communication range of up to 100m indoors and 200m in open areas (though real-world figures are more modest). Newer generations boast even greater ranges. Wi-Fi modules are essential in various portable electronics like smartphones and tablets, but it tends to be less power-efficient compared to Bluetooth and ANT+.

— Bluetooth. Developed as a universal standard for direct device-to-device connectivity, Bluetooth technology comes in several compatible versions. The latest version, Bluetooth 4.0, offers a connection range of up to 100m and incorporates a low-energy communication standard, making it more energy-efficient than Wi-Fi. This efficiency is especially beneficial for compact electronics like heart rate monitors and pedometers with limited space for a sizable battery. However, Bluetooth modules are somewhat less common than Wi-Fi, with certain tablets and laptops lacking support. This is a consideration when selecting a model with this data transfer method.

— ANT+. Designed specific...ally for sports equipment and remote control applications, ANT+ is a low-power wireless transmission technology. It facilitates connections between heart rate monitors or pedometers and various devices, including exercise machines, smartphones, and tablets. For devices with USB On-The-Go support, communication is possible through a special adapter. Higher-priced models may have built-in ANT+ support, eliminating the need for additional equipment.

The degree of water protection provided for in the design of the device.

The specified underwater depth for device functionality is often given, but it's important to note that these values are somewhat arbitrary and don't accurately reflect real-world water resistance. The assessments only consider static pressure, neglecting dynamic pressure created by movement, including immersion.

Effectively, genuine water resistance can only be claimed at a minimum of 30m. Even then, such capabilities only withstand minor exposure like rain. Brief water exposure, like swimming, might be permitted at 50m (not universally). For depths of 2 — 3m, 100m is necessary, and serious diving requires a minimum of 200m (or 300m for depths exceeding 20m).

The device has its own built-in memory.

Almost every sophisticated electronic device has a certain amount of memory, but here we specifically refer to permanent memory. This type of memory is ideal for long-term data storage, ensuring information is retained even during power outages. Its presence enables the device to operate autonomously, storing training logs, individual settings, and other essential data without the need for communication with other devices.