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 273hrs can be stored. In addition to this, there are 512 bytes of SRAM for storing application-specific information and 64 bytes for calibration data. A mission to collect data can be programmed to begin immediately, or after a user-defined delay or after a temperature alarm. Access to the memory and control functions can be password-protected.

The DS1923 is configured and communicates with a host-computing device through the serial 1-Wire® protocol, which requires only a single data lead and a ground return. Every DS1923 is factory-lasered with a guaranteed unique 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.

• Digital hygrometer measures humidity with 8-bit (0.6%RH) or 12-bit (0.04%RH) resolution
• Operating range: -20 to +85°C; 0 to 100% RH
• Automatically wakes up, measures temperature and/or humidity and stores values in 8KB of datalog memory in 8- 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 to +65°C with software correction
• Built-in humidity sensor for simultaneous temperature and humidity logging
• Capacitive polymer humidity-sensing element
• Hydrophobic filter protects sensor against dust, dirt, contaminants, and water droplets/condensation
• Sampling rate from 1s up to 273hrs
• 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 a NIST-traceable chamber
• Calibration coefficients for temperature and humidity factory programmed into non-volatile (NV) memory
• 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
• Underwriters Laboratories (UL) recognised