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Polar T31 — Review & Specs | Pricepect | Pricepect

Home Wearable Heart Rate MonitorsPolar T31

Polar T31 — image 1

Polar

Polar T31

$50.64$50.770% off

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92053125Black

Wearable Heart Rate Monitors

Expert Review Analysis

The Polar T31 Coded Chest Transmitter is a slim, fully waterproof heart‑rate sensor that delivers ECG‑level accuracy through coded transmission, eliminating crosstalk. It offers a long‑lasting non‑replaceable battery (≈2500 hours) and fits medium‑size chests, but is limited to older Polar wrist‑top computers.

✓ Best for: The T31 is best suited for runners, cyclists, cross‑country skiers, and fitness trainers who use compatible older Polar wrist‑top computers and need precise, interference‑free heart‑rate monitoring in all weather conditions, as well as researchers requiring ECG‑level data.✗ Not ideal for: It is not ideal for users of newer Polar watches (e.g., CS600, RS800, V800) or anyone needing Bluetooth/ANT+ connectivity, nor for individuals whose chest size falls outside the 25‑54 inch medium range.

Pros

✓Provides ECG‑level heart‑rate accuracy with correlation coefficients between 0.92 and 0.95 in real‑world tests.
✓Fully waterproof construction allows use in rain, swimming, and sweaty workouts without performance loss.
✓

Price History

Current

$50.64

Average

$40.50

Lowest

$33.24

Highest

$50.84

Price trend (90d):+1.2%

Best Seller Rank History

Now#215Best#88Worst#379 -7

Lower = better sales rank

Rating Trend

Rating4.1/ 5Reviews2,868+473 reviews -0.11

Specifications

Battery

Battery Life2500 hours minutes

Battery TypeNon-replaceable

Connectivity

Transmission TypeCoded

Transmission Frequency5 kHz kHz

Compatible DevicesPolar FT1, FT2, FT4, FT7, FT40, FT60, FT80, RS100, RS300X, RS400, RCX5

Design

Water Resistance100% waterproof

Strap SizeMedium (25-54 inches chest)

Transmitter Length12 inches (30.5 cm) mm

General

BrandPolar

ModelT31

Release Date2018-07-12

ColorBlack

Dimensions1 mm × 1 mm × 1 mm

Sensors

AccuracyECG-level

Signal

Transmission TypeCoded proprietary Polar transmission that prevents crosstalk

Accuracy

Correlation with ECGr=0.92‑0.95 in free‑living conditions

Fit

Strap Size RangeMedium, fits 25‑54 inches (63.5‑137 cm) chest circumference

OEM

Item Numbers003307-00 / P4400330700

Dimensions & Weight

Height0.0393700787 inches

Width0.0393700787 inches

Depth0.0393700787 inches

Weight0.0220462262 pounds

Research Sources

pmc.ncbi.nlm.nih.gov

recoveryforathletes.com

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User Reviews

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4.1

(2,868 reviews)

Coded transmission technology eliminates crosstalk, ensuring reliable data even when multiple sensors are nearby.

✓Slim, one‑piece molded plastic design with integrated elastic strap offers comfort and minimal bulk on the chest.

✓Long battery life of up to 2500 hours reduces the need for frequent replacements during training cycles.

Cons

✗Battery is non‑replaceable, so after approximately 2500 hours the entire transmitter must be discarded.
✗Incompatible with newer Polar wrist‑top computers such as the CS600, RS800, and V800 models.
✗Only a medium strap size is supplied, covering chest circumferences from 25 to 54 inches, limiting fit for smaller or larger users.
✗Lacks modern Bluetooth or ANT+ connectivity, restricting use to older Polar devices with proprietary coded link.

From Expert Reviews

Praised by Experts

✓Professional reviewers highlight its ECG‑equivalent accuracy, confirming it as a gold‑standard heart‑rate sensor.
✓Experts note the transmitter’s durability, with a 2500‑hour battery life and fully waterproof, slim construction.
✓The coded signal is praised for preventing interference from other devices, ensuring reliable data capture.

Criticized by Experts

✗Reviewers point out the non‑replaceable battery, which forces full unit replacement once the 2500‑hour lifespan ends.
✗The sensor is not compatible with newer Polar models such as the CS600, RS800, and V800, limiting its applicability.
✗Only a medium‑size strap is provided, restricting fit for users outside the 25‑54 inch chest circumference range.

From User Reviews

Users Love

✓Everyday users appreciate the consistent and accurate heart‑rate data during runs and workouts.
✓The elastic strap is described as comfortable, staying securely in place without chafing.
✓Users report reliable performance in wet conditions, thanks to the transmitter’s 100 % waterproof design.

Users Complain About

✗Customers frequently mention the non‑replaceable battery that runs out after roughly 2500 hours of use.
✗Some users experience compatibility problems when pairing the transmitter with newer Polar watches such as the V800.
✗The lack of size options beyond the medium strap leads to fit issues for users with chest sizes outside the specified range.

Expert Opinion

Professional reviewers and editors commend the T31 for its ECG‑level accuracy, robust waterproof build, and coded transmission that eliminates crosstalk, positioning it as the gold‑standard sensor for Polar’s older wrist‑top computers. However, they note drawbacks such as a non‑replaceable battery, incompatibility with newer Polar models, and limited strap sizing.

What Users Say

Everyday users praise the T31’s reliable, accurate heart‑rate readings and comfortable, waterproof design, especially for outdoor training. Recurring complaints focus on the finite, non‑replaceable battery life and occasional incompatibility with newer Polar watches, as well as the single medium strap size.

Common Complaints

Common issues include the non‑replaceable battery that expires after about 2500 hours, incompatibility with newer Polar models, and the limited medium‑only strap size.

How It Compares

vs. Polar H9

Advantages

✓Higher ECG‑level accuracy of the T31 versus the H9’s standard sport‑grade accuracy
✓Coded transmission prevents crosstalk, unlike the H9’s Bluetooth/ANT+ which can experience interference
✓Longer battery life (2500 h non‑replaceable) compared with the H9’s user‑replaceable battery of unspecified duration

Disadvantages

✗T31 lacks Bluetooth/ANT+ connectivity, limiting use to older Polar devices
✗Non‑replaceable battery means the whole unit must be discarded after its lifespan
✗Only medium strap size, whereas the H9 can be worn by a broader range of chest sizes

Choose the T31 when ECG‑grade precision and interference‑free data are critical; choose the H9 for broader device compatibility and a replaceable battery.

vs. Polar OH1+

Advantages

✓T31 provides chest‑strap ECG accuracy, which is more precise than the OH1+ optical sensor
✓Coded signal ensures reliable data in environments with multiple transmitters
✓Waterproof design and longer battery life (2500 h) surpass the OH1+’s rechargeable battery lifespan

Disadvantages

✗OH1+ offers Bluetooth/ANT+ connectivity to many devices, while the T31 is limited to older Polar models
✗OH1+ is an armband, eliminating the need for a chest strap and providing greater comfort for some users
✗T31’s non‑replaceable battery and limited strap size reduce flexibility compared with the OH1+

Select the T31 for maximum accuracy in Polar‑specific training; select the OH1+ for versatile, Bluetooth‑enabled use across multiple platforms and a more comfortable armband form factor.