Overview
The Polar T31C (Coded) Heart Rate Sensor is a streamlined, lightweight transmitter designed for precise, real-time heart rate monitoring. Unlike standard transmitters, this "coded" version uses a unique frequency to prevent "crosstalk" or interference from other nearby electronic devices, making it ideal for group training environments or busy commercial gyms. Its slim, water-resistant design ensures comfort and reliability across various athletic disciplines, from weightlifting to competitive swimming.
Product Page: Polar T31C Heart Rate Sensor - Rogue Fitness
Key Features and Specifications
Transmission Type: 5kHz Coded transmission (prevents interference from other heart rate monitors).
Battery Life: Approximately 2,500 hours of training usage.
Chest Size Compatibility: Adjustable elastic strap fits 25” to 54” chests.
Water Resistance: Fully waterproof and all-weather capable (suitable for swimming).
Form Factor: Slim, lightweight, and contoured to the body for a "zero-distraction" fit.
Compatibility: Works with most Polar-compatible gym equipment (GymLink) and wrist units.
Weight: Approximately 0.35 LBs.
Construction: Sealed polyurethane sensor unit with a textile/elastic strap.
Performance Benefits
Interference-Free Training: The coding feature ensures that the heart rate data sent to your receiver is yours alone, even if you are standing directly next to another athlete using a similar sensor.
GymLink Integration: Seamlessly connects to various cardio machines (treadmills, rowers, bikes) that support 5kHz transmission, allowing you to view your heart rate on the machine’s console.
Aquatic Versatility: Because it uses 5kHz signals, it can transmit heart rate data through water, a feature often unavailable in standard Bluetooth-only sensors.
High Accuracy: Widely recognized as a "gold standard" for consistent ECG-quality heart rate measurement during high-intensity movement.
Maintenance and Care
Rinsing: Rinse the sensor and the elastic strap under running water after every use to prevent salt and sweat buildup.
Washing: Wash the elastic strap regularly in a washing machine (40ºC/104ºF). Use a washing pouch and avoid bleach or fabric softeners.
Drying: Dry the sensor unit with a soft towel. Always hang the strap to dry; do not iron, spin-dry, or dry clean.
Storage: Never store the sensor while wet or in a non-breathing material (like a plastic gym bag). Moisture on the electrodes can keep the sensor activated, significantly shortening the battery life.
Battery Note: The battery is built-in and non-replaceable to ensure a permanent water-tight seal. Once the 2,500-hour life is exhausted, the sensor unit must be replaced.
Warranty Information
Polar provides a limited international warranty for a period of two (2) years from the date of purchase. This covers defects in materials or workmanship. The warranty does not cover the battery, damage due to misuse, improper maintenance, or unauthorized service. Proof of purchase (receipt) is required for all warranty claims.
Frequently Asked Questions
Q: Can I change the battery in the T31C myself?
A: No. The T31C is a sealed unit to maintain its waterproof integrity. The battery is non-user-replaceable. After approximately 2,500 hours of use, a new sensor unit is required.
Q: Will this sensor work with my smartphone apps via Bluetooth?
A: No. The T31C uses 5kHz GymLink technology. If you require Bluetooth or ANT+ connectivity for smartphone apps, consider the Polar H10 or H9 models.
Q: Why isn't my heart rate showing up on the gym equipment?
A: Ensure the electrodes on the back of the strap are moistened with water or conductive gel before putting it on. The sensor requires moisture to pick up your heart’s electrical signals.
Q: Can I use this for swimming?
A: Yes. The T31C is fully waterproof and the 5kHz signal is capable of transmitting through water to compatible receiving devices.