General Description

The iButton® temperature/humidity logger (DS1923) 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.

Benefits and Features

• High Accuracy, Full-Featured Digital Temperature and Humidity Logger Simplifies Temperature Data Collection and Dissemination of Electronic Temperature Record

    • Digital Hygrometer Measures Humidity with 8-Bit (0.6RH) or 12-Bit (0.04RH) Resolution

    • Temperature Accuracy Better Than ±0.5°C from -10°C to +65°C with Software Correction

    • Measures Temperature with 8-Bit (0.5°C) or 11-Bit (0.0625°C) 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

    • Built-In Capacitive Polymer Humidity Sensor for Humidity Logging

    • Sampling Rate from 1s Up to 273hr

    • Programmable High and Low Trip Points for Temperature and Humidity Alarms

    • Programmable Recording Start Delay After Elapsed Time or Upon a Temperature Alarm Trip Point

    • 512 Bytes of General-Purpose Memory Plus 64 Bytes of Calibration Memory

    • Two-Level Password Protection of All Memory and Configuration Registers

    • Individually Calibrated in a NIST-Traceable Chamber

    • Calibration Coefficients for Temperature and Humidity Factory Programmed Into Nonvolatile (NV) Memory

• Rugged Construction Survives Harsh Environments

    • Hydrophobic Filter Protects Sensor Against Dust, Dirt, Contaminants, and Water Droplets/ Condensation with IP56 Enclosure Rating

    • CE, FCC, and UL913 Certifications

• Simple Serial Port Interfaces to Most Microcontrollers for Rapid Data Transfer

    • Communicates to Host with a Single Digital Signal Up to 15.4kbps at Standard Speed or Up to 125kbps in Overdrive Mode Using 1-Wire Protocol

    • Quick Access to Alarmed Devices Through 1-Wire Conditional Search Function

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