Specifications

73Sensors: Featured Products
Digital Temperature/Humidity Data Logger
Ensures Accurate Reading
DS1923
The DS1923 temperature/humidity logger Hygrochron iButton is a rugged, self-
sucient system that measures temperature and/or humidity and records the
result in a protected memory section. The recording is done at a user-dened
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-specic information and 64 bytes store calibration
data. A mission to collect data can be programmed to begin immediately,
after a user-dened delay, or after a temperature alarm. Access to the memory
and control functions can be password protected. The DS1923 is congured
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.
Accessories permit the DS1923 to be mounted on almost any object, including
containers, pallets, and bags.
Benefits
• Sophisticated, flexible temperature
logging protects product integrity
◦ Automatically wakes up and
measures temperature and/or
humidity
◦ Stores temperature and humidity
values in 8KB of data-log memory in
8-bit or 16-bit format
◦ 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
• Precise humidity and temperature
measurement ensure accurate logging
◦ 0.5°C or 0.0625°C temperature
resolution
◦ ±0.5°C temperature measurement
accuracy 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
◦ Measures humidity with 5%
accuracy, 8-bit (0.6% RH) or 12-bit
(0.04% RH) resolution
• Rugged and small container provides
robustness and usage flexibility
◦ Strong stainless steel enclosure
◦ Complete solution in less that 0.1
cubic inch
• Safe, secure logging
◦ Two-level password protection of all
memory and configuration registers
◦ Operating Range: -20°C to +85°C
◦ 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
GENERAL-PURPOSE
SRAM
(512 BYTES)
CALIBRATION MEMORY
(64 BYTES)
REGISTER PAGES
(64 BYTES)
MEMORY
FUNCTION
CONTROL
64-BIT
LASERED
ROM
256-BIT
SCRATCHPAD
CONTROL
LOGIC
HUMIDITY
SENSOR AND
ADC2
32.768kHz
OSCILLATOR
3V LITHIUM
IO
THERMAL
SENSE
ADC1
DATA-LOG MEMORY
8KB
INTERNAL
TIMEKEEPING,
CONTROL REGISTERS,
AND COUNTERS
ROM
FUNCTION
CONTROL
1-Wire PORT
PARASITE-POWERED
CIRCUITRY
DS1923