General Description
The DS1923 temperature/humidity logger iButton® is a rugged, self-sufficient system that measures temperature and/or humidity and records the result in a protected memory section. The recording is done at a user-defined rate. A total of 8192 8-bit readings or 4096 16-bit readings, taken at equidistant intervals ranging from 1s to 273hr, can be stored. Additionally, 512 bytes of SRAM store application-specific information and 64 bytes store calibration data.

FEATUREs
♦ Digital Hygrometer Measures Humidity with 8-Bit (0.6%RH) or 12-Bit (0.04%RH) Resolution
♦ Operating Range: -20°C to +85°C; 0 to 100%RH (see Safe Operating Range Graph)
♦ Automatically Wakes Up, Measures Temperature and/or Humidity, and Stores Values in 8KB of Data-Log Memory in 8-Bit or 16-Bit Format
♦ Digital Thermometer Measures Temperature with 8-Bit (0.5°C) or 11-Bit (0.0625°C) Resolution
♦ Temperature Accuracy Better Than ±0.5°C from -10°C to +65°C with Software Correction
♦ Built-In Capacitive Polymer Humidity Sensor for Humidity Logging
♦ Hydrophobic Filter Protects Sensor Against Dust, Dirt, Contaminants, and Water Droplets/Condensation
♦ Sampling Rate from 1s Up to 273hr
♦ Programmable Recording Start Delay After Elapsed Time or Upon a Temperature Alarm Trip Point
♦ Programmable High and Low Trip Points for Temperature and Humidity Alarms
♦ Quick Access to Alarmed Devices Through 1-Wire Conditional Search Function
♦ 512 Bytes of General-Purpose Memory Plus 64 Bytes of Calibration Memory
♦ Two-Level Password Protection of All Memory and Configuration Registers
♦ Communicates to Host with a Single Digital Signal at Up to 15.4kbps at Standard Speed or Up to 125kbps in Overdrive Mode Using 1-Wire Protocol
♦ Individually Calibrated in an NIST-Traceable Chamber
♦ Calibration Coefficients for Temperature and Humidity Factory Programmed Into Nonvolatile (NV) Memory

Common iButton Features
♦ Digital Identification and Information by Momentary Contact
♦ Unique Factory-Lasered 64-Bit Registration Number Ensures Error-Free Device Selection and Absolute Traceability Because No Two Parts Are Alike
♦ Built-In 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
♦ Meets UL 913, 5th Ed., Rev. 1997-02-24; Intrinsically Safe Apparatus: Approved Under Entity Concept for Use in Class I, Division 1, Group A, B, C, and D Locations

APPLICATIONs
    Temperature and Humidity Logging in Food Preparation and Processing
    Transportation of Temperature-Sensitive and Humidity-Sensitive Goods, Industrial Production
    Warehouse Monitoring
    Environmental Studies/Monitoring