DALLAS SEMICONDUCTOR DS1921L-F50 Semi Thermochron Logger 1-WIRE Temperature Ibutton

( Brand: Dallas Semiconductor ), ( Manufacturer Part Number: DS1921L-F50 ), ( Model: IBUTTON )

Review DALLAS SEMICONDUCTOR Vintage Semi 1-wire Thermochron Temperature Logger Ibutton

The Dallas Semiconductor DS1921G-F5 and DS1921L-F50 are advanced 1-Wire temperature loggers, also known as iButton thermochrons, designed for various applications where accurate and reliable temperature recording is essential. These compact, coin-shaped devices offer outstanding performance, ease of use, and flexibility in temperature monitoring.

The DS1921G-F5 and DS1921L-F50 are built using 1-Wire technology, which simplifies communication between multiple devices using just a single data line. Each device comes with a unique 64-bit serial number, making it easy to identify and manage individual loggers in a system.

Both DS1921G-F5 and DS1921L-F50 loggers have a small form factor, measuring just 1.37 inches long and 0.5 inches wide, making them ideal for applications where space is limited. They are designed to be used in harsh environments and can withstand temperatures ranging from -40 C to 85 C (-40 F to 185 F).

These temperature loggers feature an integrated temperature sensor with a high degree of accuracy, ensuring precise temperature readings. They can store up to 8,192 temperature readings, with each measurement having a user-selectable time interval between readings, ranging from 1 second to 2150 minutes.

The DS1921G-F5 comes with a factory-set 91.5 C high-temperature alarm, while the DS1921L-F50 offers a user-configurable high-temperature alarm, allowing you to set the threshold to your specific requirements. Additionally, both loggers support multiple conversion temperatures, enabling users to calculate temperatures based on various conversion equations.

To read and communicate with these temperature loggers, you will need a compatible 1-Wire interface, such as a DS9490R or DS9498R reader, which is sold separately. The simple and efficient 1-Wire communication protocol makes it easy to read data from multiple DS1921G-F5 and DS1921L-F50 loggers simultaneously.

In summary, the Dallas Semiconductor DS1921G-F5 and DS1921L-F50 temperature loggers are excellent choices for various applications where accurate and reliable temperature recording is essential. Their compact size, rugged design, and easy-to-use 1-Wire interface make them ideal for monitoring temperatures in harsh environments, laboratories, industrial processes, and more.

The Dallas Semiconductor DS1921G-F50 thermochron temperature logger, also known as an iButton, is a popular choice for those seeking a small, self-contained, and easy-to-use data logging solution. Here are some pros and cons of buying this particular model:

1. Compact Size: With a small form factor of just over an inch long, the DS1921G-F50 can be easily integrated into various applications where space is a concern.

2. Wide Temperature Range: The temperature sensor inside the iButton can measure temperatures between -40 C and 85 C (-40 F and 185 F), making it suitable for a wide range of environments.

3. Long Battery Life: The DS1921G-F50 comes with a CR2032 coin cell battery that can last up to 5 years, depending on the logging interval and temperature range.

4. High Accuracy: The temperature sensor inside the iButton offers a high degree of measurement accuracy, making it suitable for various industrial and scientific applications.

5. One-Wire Communication: The DS1921G-F50 uses Dallas Semiconductor's One-Wire communication protocol, which simplifies the connection process and reduces the need for additional wiring.

1. Limited Data Storage: The DS1921G-F50 can store up to 4,096 temperature readings, which may not be sufficient for applications that require extensive data logging.

2. Limited Logging Intervals: The logging interval is fixed at 30 seconds, which may not be suitable for applications that require more frequent data sampling.

3. Non-Replaceable Battery: The CR2032 coin cell battery inside the iButton is not user-replaceable, meaning the entire iButton needs to be replaced when the battery dies.

4. Limited Communication Distances: The DS1921G-F50 can only communicate with the reader or computer up to a maximum distance of 1 meter (3 feet) without using a repeater or signal amplifier.

The Dallas Semiconductor DS1921G-F50 iButton offers a compact, accurate, and easy-to-use temperature logging solution with long battery life and wide temperature range. However, it has limitations in terms of data storage capacity, logging intervals, non-replaceable battery, and communication distances.

If your application requires a small, self-contained temperature logger with a long battery life and wide temperature range, the DS1921G-F50 iButton is an excellent choice. However, if you need more extensive data logging capabilities, a replaceable battery, or longer communication distances, you may want to consider alternative solutions. Additionally, consider checking out other iButton models from Dallas Semiconductor or other manufacturers to find the best fit for your specific application.

Details:

The iButton model features a compact, waterproof design and has wide range of temperature measurement capabilities. This vintage electronic device is perfect for monitoring and recording temperature levels in various applications, making it a valuable addition to any electronics collection. Mounted in key fob. It is a one-wire device that allows for accurate temperature readings and logging.

The Vintage Dallas Semi 1-wire THERMOCHRON temperature logger iButton DS1921L-F50 is a digital thermometer manufactured by Semiconductor.

part #: ds1921lf50 price

• $19.99

specifications vintaelec:

• brand: Dallas Semiconductor
• mpn: Ds1921l-f50
• model: Ibutton

seller vintaelec:

• rating: 100.0%
• # reviews: 359
• city: Powhatan, Virginia

general vintaelec:

• condition: Used
• Consumer Electronics > Vintage Electronics > Other Vintage Electronics

offer vintaelec:

• options: Ship-to-home
• quantity: 1
• best offers: True
• availability: In Stock
• sold: 0
• started: April 14, 2026

returns vintaelec:

• policy: No Returns

payments vintaelec:

• credit card: Visa
• other
• wallet: Google-pay

shipping vintaelec:

• service: USPS Ground Advantage
• cost: $4.78
• carrier: USPS
• transit: 4-10 Days
• type: Fixed
• class: Standard

Dallas Semiconductor DS1921L-F50 Is Similar To:

• Dallas Ds1213 Nos Vintage Electronics Smart Socket (45.4% similar) These are from a long time collector who used and saved thousands of components during his career. Please see photos for more details...(September 14th, 2025)