Half a year ago, the 37 degree bracelet was the most affordable heart rate detection intelligent device. After upgrading the firmware, it became the first product supporting continuous heart rate detection and recording in China. The manufacturer also recently launched a luxury 37 degree bracelet with a colorful watch strap.
In this evaluation report, in addition to the conventional appearance and software experience, we mainly conduct a comprehensive test on its heart rate/blood pressure/breathing detection. Don't talk nonsense, let's see the result now:
parameter
It weighs 21g and supports IP54 waterproof
The luxury edition provides black, red and bright blue watchbands. It is rumoured that a limited edition of red gold will be launched this month
157mAh battery, 5-7 days in normal use, can continuously measure heart rate for about 10 hours
Using Bluetooth 4.0, supporting iOS7 and Android 4.3+devices
Appearance and workmanship
The luxury 37 degree bracelet has a simple package, with parameters and accessories on the back.
The first layer of the package is the bracelet body and buckle, and the second layer is the accessory box and instructions.
The luxury version includes two snap charging bases. The polished back is very beautiful, but it is easy to scratch when it is placed at ordinary times.
The base can be powered by computer USB port or mobile phone charger, and it takes about 1.5 hours to fully charge. After adding one more charger, you can put one at home and one at the office. You don't need to remember where to charge it. It will be easier to use.
The package also includes red, light blue and black silicone watchband. There are uniform stripes on the watchband, which belongs to hard silicone, with good flexibility and touch.
The metal cover plate with dot matrix decoration on the front of the bracelet has bright chamfers on the side, which has a high face value. At the center of the back of the arc is a huge heart rate sensor and charging contact.
The core part of the bracelet is larger, and it is more like a smart watch with the strap. The silicone strap and the core have a high bite tightness, so even if you squeeze hard, it is impossible for the core to fly off.
The color of the colorful watchband is bright, small and fresh. There is no difference in touch. You can choose it according to your preference.
The watchband itself is a waste product. It's also good to have several watchbands in reserve. Of course, it would be better if the strap could be purchased independently instead of being selected by force.
Contrast and wearing feeling
From left to right are the heart rate version of the millet bracelet (almost the same size as the ordinary version), the 37 degree bracelet and Samsung's Gear Fit.
From left to right are the 42mm dial version of Apple Watch, 37 degree bracelet and LG G Watch Urbane. The length of the core part of the 37 degree bracelet has even exceeded that of the real smart watch, but the width advantage is obvious.
The wearing comfort of the bracelet/watch is directly related to the size, weight and strap width of its main part: the wearing feeling of the 37 degree bracelet is close to Gear Fit, and the sense of existence is more obvious than the smallest Xiaomi bracelet, but slightly better than the larger smart watch.
Heart rate sensing devices must be worn tightly to measure heart rate correctly. It is unrealistic to say how comfortable they are. For many users, it still takes some time to adapt to their sense of existence.
Function and use
In terms of function, the smart bracelet is a decoration worn on the body to record the movement status and occasionally remind through vibration/indicator light. They have four traditional functions: step counting, sleep monitoring, vibrating alarm clock and message push.
The function setting of the 37 degree bracelet is quite radical. The vibrating alarm clock and message push function are canceled. It is a complete detection device. In the detection part, besides step counting/sleep and heart rate, there are rare detection functions such as blood pressure/respiration/mood. Daily use indicates working/charging status through the hidden indicator light on the front.
In terms of endurance, if manual measurement is not carried out, normal wear can last for 6 or 7 days. After opening the continuous heart rate measurement mentioned below, it can last for 10 hours. 0-100% charging takes about 1.5 hours. The endurance is close to the bracelets with screen/heart rate such as Fitbit Charge and Gear Fit, which is better than smart watches and much weaker than the bracelets without screen such as the generation Xiaomi bracelet, but it is no longer a big problem.
App
The whole app is also around the detection data. The main interface lists the detection data, and the active detection function entry is in the left column.
The biggest difference between it and the ordinary bracelet is that it provides periodic heart rate monitoring. Each punctual point will automatically measure heart rate/blood pressure/respiration and other data, which can be automatically measured without interference, just like a pedometer.
Monitoring statistics of heart rate, respiration and blood pressure. Slide in the data table to view the original data
Apart from counting steps and sleeping, its selling point is the rare detection of heart rate, blood pressure, breathing, mood/fatigue. The statistics of the data are very detailed, and there are numerical values to intuitively display the health degree and corresponding health suggestions. The blood pressure value inside has even been made into a curve to compare with the ideal situation.
Comparison of two consecutive heart rate measurements
In the new version, the continuous heart rate measurement function is added. After opening, the detection cycle of heart rate/blood pressure will be shortened to tens of seconds, and finally the heart rate fluctuation curve will be obtained for a period of time. As for the use and actual experience, we will talk about it in detail below.
Step accuracy
From left to right are 37 degree bracelets, Xiaomi bracelets and Samsung Gear Fit step counting statistics
At the same time, wear a 37 degree bracelet, a heart rate version of the millet bracelet and Samsung Gear Fit, and select the most representative day for comparison:
Step counting accuracy: The step counting results of the 37 degree bracelet (8963 steps) and the millet bracelet (9163 steps) are relatively close, much larger than the Samsung Gear Fit (7252 steps). Interestingly, however, even though the first two have the same number of steps, their distance and calorie statistics are significantly different.
Data statistics details: Xiaomi bracelet is the worst. It can only record the detailed steps of the day. The previous data will be reduced to a few simple figures; Samsung will at least keep a detailed statistical table; The statistical table of the 37 degree bracelet is not as detailed as Samsung, but it will keep a record of the number of steps per hour, which is quite good.
Sleep detection
Prediction of sleeping/waking time points: except that Gear Fit needs to manually enter and exit the sleep mode, the other two can be automatically recognized, and the time points of sleep in and out are accurately inferred, with an error of 5-10 minutes, which shows good performance;
Depth sleep statistics: the three are very close, 37 degrees and millet are marked with more intuitive hours, while Gear Fit uses percentage;
Data fineness/accuracy: all three basically conform to the actual law that the more you sleep, the shallower you sleep. The statistical data of the 37 degree bracelet is a little more precise than that of the Xiaomi bracelet, but it is still far from Gear Fit. The latter can even see the real changes of the fourth level sleep stage.
Principle of heart rate and blood pressure measurement
This is the core part of the 37 degree bracelet. It is the first domestic bracelet that supports heart rate detection. After the firmware upgrade, it also introduces the function of continuous heart rate measurement.
It adopts the optical detection method: the machine emits light to illuminate the skin of the hand. When the blood flows through the capillaries, the light brightness (red depth) will have a slight change. The sensor detects the change of the reflected light, and the data of heart rate, blood pressure, respiration, mood and fatigue can be obtained through the algorithm.
When detecting the heart rate, the 37 degree bracelet uses the two green LED light sources above; When detecting blood pressure and respiratory rate, use the two white LED light sources below. The optical data are received by two optical sensors in the center.
Comparison of heart rate sensors size of Xiaomi bracelet, 37 degree bracelet and Gear Fit
Apple Watch、 Heart rate sensor size comparison between 37 degree bracelet and LG G Watch Urbane
The accuracy of heart rate sensor is directly related to its light source intensity and receiver sensitivity. In order to improve the accuracy of heart rate/blood pressure data, a heart rate sensor that is a large part larger than its peers is inserted into the 37 degree bracelet.
Emotion and fatigue detection
With this huge heart rate sensor, 37 degrees can measure five kinds of data, including heart rate, blood pressure, respiratory rate, mood and fatigue. Among them, blood pressure and respiration are professional items rarely seen in civilian products. Although it seems that the prediction is reliable at ordinary times, there is no actual measurement standard for the detection of mood and fatigue. It would be better to take it as health advice.
Heart rate, respiratory rate and blood pressure detection
The bracelet will take a complete measurement every hour, and each project will take 20 seconds to 2 minutes, and finally will be connected into a whole day's data graph. This should be the only wearable device on the market that can automatically detect heart rate. The heart rate function of similar products needs to be turned on manually or in exercise mode.
The experience advantage of the 37 degree bracelet is that it can have 24 times of detection data a day without intervention, which is the proper form of heart rate detection equipment, and is much more humanized than similar products that need manual detection. However, there are too many changes in a day, and the data curve is difficult to be close to the so-called health standard.
Static accuracy
Use the real heart rate/detection equipment for comparison, and the testing machine is the Vtion handheld quality inspection instrument.
The left hand is equipped with Gear Fit, 37 degree bracelet and self detector at the same time, and multiple tests are carried out when the left hand is still. The mobile phone on the left is the reading of the 37 degree bracelet, and the right is the reading of the self-test.
Heart rate: the resting heart rate measured by the three is between 65-67. The measuring speed of the 37 degree bracelet is slower than that of the Gear Fit, but the reading should be more stable and close to the result of the self-test.
Blood pressure: The blood pressure test result of the 37 degree bracelet is also very close to that of the self inspection device, but the reading of the former is not as stable as that of the latter, and the reading of high and low pressure tends to be slightly larger.
Respiratory rate: Compared with the manual reading, there is no obvious difference between multiple measurements. Even the artificial control of respiratory rate can have correct readings, with good accuracy and adaptability.
Motion accuracy test
Continuous heart rate measurement interface (first from left) and data statistics (middle and right figure)
The continuous heart rate measurement function of the 37 degree bracelet is similar to the exercise mode of similar products, and can display the heart rate and steps in real time. After the exercise, in addition to statistical data, there is also a heart rate curve. This is the biggest selling point of the 37 degree bracelet, which is the only one in China for the time being.
What's more special is that even in this mode, the heart rate sensor is not always on like similar products, and there will be a gap of about 20 seconds between each measurement. This may be the reason why it can run for 10 hours in this mode, while similar products can only run for 4 or 5 hours.
Use push ups with regular movement rhythm and climbing stairs as test items. Wear a millet bracelet and a 37 degree bracelet in the left hand, and a Gear Fit and Apple Watch in the right hand.
The initial heart rate of push ups is 81-83 times/minute. The upper row is millet bracelet and 37 degree bracelet; The lower row is Gear Fit and Apple Watch readings.
Comparison of readings after 2 minutes of 40 push ups
Accuracy: the readings of the four devices are between 99-105, with a small gap.
Detection speed: There are obvious differences among the four devices. The first change is the Gear fit in the lower left corner, followed by the 37 degree bracelet. After about 30 seconds, the Xiaomi bracelet also has a correct reading. However, the Apple Watch had to wait another half minute to get the correct reading, and the problem of reading drift also occurred.
Climb 9 floors of stairs for 3 minutes, and take readings when going down the stairs to simulate normal movement. The upper row is Xiaomi bracelet, 37 degree bracelet, Samsung S6 edge machine with heart rate sensor readings; The lower row is Gear Fit and Apple Watch readings.
Stable reading speed: Gear Fit and 37 degree bracelet are still the fastest, followed by Xiaomi bracelet and Apple Watch;
Precision: The readings of Gear Fit and Apple Watch are the closest. Both the Xiaomi bracelet and the 37 degree bracelet are small and have the problem of data drift. The 37 degree bracelet is more obvious.
Because they have to be worn tightly, the four devices will leave marks on the hands after intense and long exercise. The most obvious are Gear Fit and 37 degree bracelets (of course, this is related to the fact that they are worn on the outside), followed by Xiaomi bracelets and Apple Watch.
Result analysis
When the photoelectric heart rate detection equipment is in motion, because the distance between the detector and the lower skin changes and affects the accuracy, it is recommended to measure at rest. In order to have usable accuracy during exercise, you need to wear them very tightly. It is better to swing your arm without seeing the light leakage of the heart rate sensor (the author is not thin enough to cover the light sensor, and the accuracy of motion detection will be a little lower than that of fat people).
In actual movement, all four products have occasional reading drift, but the Xiaomi bracelet and the 37 degree bracelet are relatively more obvious. Gear Fit has the best comprehensive performance.
Although the final reading of the Apple Watch is stable and accurate, the speed of reading change and stability is extremely slow. The heart rate reading can be stabilized in 1-2 minutes, and many data may be missed in the middle;
The highest value of the 37 degree bracelet is low, and occasionally the data is significantly lower;
The highest value of Xiaomi bracelet is also low, and the data is stable and slow. It is worth noting that the reading changes almost every second, but the speed of stabilizing the reading is slower than that of Gear Fit and 37 degree bracelet. It can basically be considered that the middle change is algorithm interpolation. Let's have a look at the data of high-speed jumping.
data statistics
On the left is Gear Fit, and on the right is the data statistics after the Xiaomi bracelet movement
On the left is the data statistics of Apple Watch when climbing stairs, and on the right is the motion statistics of push ups
They can continuously measure heart rate in exercise mode. But strangely, Apple Watch、Gear Fit、 The Xiaomi bracelet does not retain all the heart rate data. At most, it only retains the maximum, minimum and average heart rates. Many data are lost during exercise.
37 degree bracelet movement statistics, numerical statistics on the left and continuous heart rate curve on the right
The 37 degree bracelet shows the advantage of rolling in heart rate statistics, and all heart rate data during the whole exercise period are included in it. As you can see in the above figure, the heart rate of several groups of push ups is from the left to the peak in the center, and the heart rate of climbing stairs is the peak on the right.
Daily continuous heart rate detection data
The first one on the left is the heart rate statistics when sleeping at night. From the peak of heart rate, you can even infer which time points did not sleep well. At several time points when the heart rate soared, it was probably a nightmare (or the bracelet was loosened when kicking the quilt).
Heart rate data when walking and exercising
Through the height and peak duration of the heart rate curve, as well as the notes on the left side of the chart, we can know our exercise efficiency when doing different exercises, so as to adjust the type and frequency of exercise. This is a very killer function for real fitness or weight loss users.
If it is detected that this exercise can keep your heart rate at a high level for a long time, it shows that its cardio pulmonary exercise effect is very obvious. If the heart rate keeps at a low level, it can only be considered as fat burning or even ordinary decompression exercise. Even if you don't do regular exercise, these heart rate data are very meaningful for improving and guiding your daily life (will your heart rate be a little too excited when you are LOL, and your heart rate will soar when you run two steps, so it's time to do some exercise?).
Although it is only an improvement in continuous heart rate measurement and data statistics, the whole heart rate recording experience has exploded 99% of heart rate products. Strangely, only 37 bracelets in China now have such a function. Maybe other manufacturers just regard heart rate as a subsidiary function.
Of course, the experience of the 37 degree bracelet has not yet reached the perfect level. The data volume of continuous heart rate is huge, and it is recorded by mobile phone data when measuring, so you have to take your mobile phone with you to record continuous heart rate during exercise; When viewing a specific project, its app can't directly switch between the left and right dates. It can only manually turn over the data of the day on the home page. Horizontal comparison is not convenient.
Summary analysis
Hardware: The 37 degree bracelet has a good appearance and feel. The charging frequency and waterproof level are also the normal level of the heart rate bracelet, and there is not much difference.
Use: It is a completely non-interference experience. You can occasionally open the app to view the cycle record, which is very easy to use. But there is no vibrating alarm clock and notification reminder, and it is even more impossible to display the time (these are the pits that can only be filled by the second generation products).
Step counting and sleep accuracy: The normal level of the domestic bracelet is slightly better than the heart rate version of the Xiaomi bracelet, but there is still a certain distance from the international manufacturers. Although there is no map and track recording function in the exercise mode, Shengzai can retain specific data every day;
Detection accuracy of heart rate/blood pressure/respiration: the individual measurement at rest is more accurate, and is close to the data of professional instruments. The speed of refreshing and stabilizing in motion measurement is faster than that of Xiaomi bracelet and Apple Watch. The accuracy of medium and low heart rates, which account for the highest proportion in daily life, is close to that of similar products, but there is a problem that the maximum value is too small. It is not confirmed that it is an individual case or an algorithm bug for the time being.
Continuous heart rate detection: This is the unique function advantage of the 37 degree bracelet. In addition to the advantage of 10 hour continuous measurement, it can record the heart rate curve of the whole process (but there is no way to view specific data), which is very practical for daily life or exercise.
Price: 199 yuan for the luxury version includes two additional wristbands and one charger. Compared with foreign products, it has obvious price advantages, but it is actually a little expensive among domestic bracelets. As a comparison, the market price of Samsung Gear Fit is 998 yuan (it dropped to 500 yuan at the lowest time, but now many channels are out of stock); The heart rate version of Xiaomi bracelet with heart rate, vibrating alarm clock and message reminder is 99 yuan (his heart rate is meaningless...); A large number of unknown domestic bracelets are priced between 79-200 yuan. Although almost all have no heart rate function, some products even have time display function.
The 37 degree bracelet is a real health bracelet. It is also one of the most professional bracelets for health monitoring in China. Its continuous heart rate detection function is highly practical, and it is very sensitive to the taste of data maniacs and healthy users. In terms of actual experience and function availability, it can fully afford its own price.
But it really only has the detection function. The cost of adding the detection function of heart rate/blood pressure/respiration is that it gives up the common functions such as vibrating alarm clock and message push. This is the choice made by the manufacturer after weighing the gains and losses. It is good for everyone to measure their functional needs before buying.
The above is all the contents of this evaluation report. More experiences and evaluations of smart products are welcome to scan the QR code below Love to play computer games Official WeChat.
