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High-Resolution Thermochron iButton Devices

Product Details

The Thermochron® iButton® devices (DS1921H/Z) are rugged, self-sufficient systems that measure temperature and record the result in a protected memory section. The recording is done at a user-defined rate, both as a direct storage of temperature values as well as in the form of a histogram. Up to 2048 temperature values taken at equidistant intervals ranging from 1 to 255 minutes can be stored. The histogram provides 64 data bins with a resolution of 0.5°C. If the temperature leaves a user-programmable range, the DS1921H/Z will also record when this happened, for how long the temperature stayed outside the permitted range, and if the temperature was too high or too low. Additional 512 bytes of general-purpose battery-backed SRAM allow storing information pertaining to the object to which the DS1921H/Z is associated. Data is transferred serially via the 1-Wire® protocol, which requires only a single data lead and a ground return. Every DS1921H/Z is factory-lasered with a guaranteed unique electrically readable 64-bit registration number that allows for absolute traceability. The durable stainless steel package is highly resistant to environmental hazards such as dirt, moisture, and shock. Accessories permit the DS1921H/Z to be mounted on almost any object, including containers, pallets, and bags.

Key Features

  • Digital thermometer measures temperature 1/8°C increments with ±1°C accuracy
  • Built-in real-time clock (RTC) and timer has accuracy of ±2 minutes per month from 0°C to 45°C
  • Water resistant or waterproof if placed inside DS9107 iButton capsule (Exceeds Water Resistant 3 ATM requirements)
  • Automatically wakes up and measures temperature at user-programmable intervals from 1 to 255 minutes
  • Logs consecutive temperature measurements in 2KB of datalog memory
  • Records a long-term temperature histogram with 1/2°C resolution
  • Programmable temperature-high and temperature-low alarm trip points
  • Records up to 24 time stamps and durations when temperature leaves the range specified by the trip points
  • 512 bytes of general-purpose battery-backed SRAM
  • Communicates to host with a single digital signal at 15.4kbits or 125kbits per second using 1-Wire protocol
  • Fixed range: H: +15°C to +46°C; Z: -5°C to +26°C
Common iButton Features
  • Digital identification and information by momentary contact
  • Unique, factory-lasered and tested 64-bit registration number (8-bit family code + 48-bit serial number + 8-bit CRC tester) assures absolute traceability because no two parts are alike
  • Multidrop controller for 1-Wire net
  • Chip-based data carrier compactly stores information
  • Data can be accessed while affixed to object
  • Button shape is self-aligning with cup-shaped probes
  • Durable stainless steel case engraved with registration number withstands harsh environments
  • Easily affixed with self-stick adhesive backing, latched by its flange, or locked with a ring pressed onto its rim
  • Presence detector acknowledges when reader first applies voltage

Applications/Uses

Parametric specs for Data Loggers
Interface 1-Wire
Technology iButton
Applications Asset Management
Usage Multi Use
Memory Type SRAM
Memory Size 4K bits
Data Logger Type Temperature
Temp. Readings 2048
Oper. Temp. (°C) +15 to +46
Budgetary
Price (See Notes)
$20.99 @1k
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Simplified Block Diagram

DS1921H, DS1921Z: High Resolution Thermochron DS1921H, DS1921Z: High Resolution Thermochron Zoom icon

Design & Development

Click any title below to view the detail page where available.

Additional Resources
1-Wire Temp Logger Calculator

Description

The DS1921K Thermochron iButton® Starter Kit provides the basic hardware for a quick evaluation of Maxim’s Thermochron iButton family that communicates using the 1-Wire® protocol. The kit uses the USB port of a Microsoft Windows®-based Personal Computer running Vista®, XP SP2 (or higher), or Microsoft Server Operating Systems Windows 2003 or 2008. The kit includes a DS1921 Thermochron iButton device and all hardware required to communicate with it. The DS1921K is also capable of evaluating any other iButton devices, including the high-capacity Thermochron devices (DS1922L, DS1922T, and DS1923), the Hygrochron device (DS1923), and the temperature-only iButton device (DS1920). Please note that the DS1921 is the only iButton device included in the kit. All other iButton devices may be purchased separately. The easy setup process includes the free download of 1-Wire drivers and the OneWireViewer demonstration software to easily communicate with iButton devices through the PC's USB port. The download site for the free 1-Wire drivers and bundled OneWireViewer is found at:

www.maximintegrated.com/1-wiredrivers

For software developers who wish to create custom iButton applications, Maxim provides documentation and a free library of source code examples at www.maximintegrated.com/ibutton under the Software Development Kits link. Please check our website regularly for software updates.

To evaluate plastic-packaged 1-Wire devices instead of the iButton form factor, use the DS9090K instead of the DS1921K. To evaluate other iButton devices besides the Thermochron devices, see the DS9092K.

EV Kit Contents

QTY DESCRIPTION
1 DS1921G-F5# Thermochron iButton
1 DS9093F Snap-in Fob, Black
1 DS1402D-DR8 dual Blue Dot™ Receptor
1 DS9490R USB to 1-Wire adapter

View Details

Features

  • Starter Kit to evaluate the DS1921 Thermochron iButton temperature recording device with a Microsoft Windows-based PC
  • Easy Setup with USB Adapter
  • Free download of 1-Wire drivers and OneWireViewer Demonstration Software
  • Compatible with other Thermochron iButton devices DS1922L, DS1922T, DS1922E, DS1923 (not included)

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Support & Training

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Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal.

Parameters

Parametric specs for Data Loggers
Interface 1-Wire
Technology iButton
Applications Asset Management
Usage Multi Use
Memory Type SRAM
Memory Size 4K bits
Data Logger Type Temperature
Temp. Readings 2048
Oper. Temp. (°C) +15 to +46
Budgetary
Price (See Notes)
$20.99 @1k

Key Features

  • Digital thermometer measures temperature 1/8°C increments with ±1°C accuracy
  • Built-in real-time clock (RTC) and timer has accuracy of ±2 minutes per month from 0°C to 45°C
  • Water resistant or waterproof if placed inside DS9107 iButton capsule (Exceeds Water Resistant 3 ATM requirements)
  • Automatically wakes up and measures temperature at user-programmable intervals from 1 to 255 minutes
  • Logs consecutive temperature measurements in 2KB of datalog memory
  • Records a long-term temperature histogram with 1/2°C resolution
  • Programmable temperature-high and temperature-low alarm trip points
  • Records up to 24 time stamps and durations when temperature leaves the range specified by the trip points
  • 512 bytes of general-purpose battery-backed SRAM
  • Communicates to host with a single digital signal at 15.4kbits or 125kbits per second using 1-Wire protocol
  • Fixed range: H: +15°C to +46°C; Z: -5°C to +26°C
Common iButton Features
  • Digital identification and information by momentary contact
  • Unique, factory-lasered and tested 64-bit registration number (8-bit family code + 48-bit serial number + 8-bit CRC tester) assures absolute traceability because no two parts are alike
  • Multidrop controller for 1-Wire net
  • Chip-based data carrier compactly stores information
  • Data can be accessed while affixed to object
  • Button shape is self-aligning with cup-shaped probes
  • Durable stainless steel case engraved with registration number withstands harsh environments
  • Easily affixed with self-stick adhesive backing, latched by its flange, or locked with a ring pressed onto its rim
  • Presence detector acknowledges when reader first applies voltage

Applications/Uses

Description

The Thermochron® iButton® devices (DS1921H/Z) are rugged, self-sufficient systems that measure temperature and record the result in a protected memory section. The recording is done at a user-defined rate, both as a direct storage of temperature values as well as in the form of a histogram. Up to 2048 temperature values taken at equidistant intervals ranging from 1 to 255 minutes can be stored. The histogram provides 64 data bins with a resolution of 0.5°C. If the temperature leaves a user-programmable range, the DS1921H/Z will also record when this happened, for how long the temperature stayed outside the permitted range, and if the temperature was too high or too low. Additional 512 bytes of general-purpose battery-backed SRAM allow storing information pertaining to the object to which the DS1921H/Z is associated. Data is transferred serially via the 1-Wire® protocol, which requires only a single data lead and a ground return. Every DS1921H/Z is factory-lasered with a guaranteed unique electrically readable 64-bit registration number that allows for absolute traceability. The durable stainless steel package is highly resistant to environmental hazards such as dirt, moisture, and shock. Accessories permit the DS1921H/Z to be mounted on almost any object, including containers, pallets, and bags.

Simplified Block Diagram

DS1921H, DS1921Z: High Resolution Thermochron DS1921H, DS1921Z: High Resolution Thermochron Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal.