|
Accuracy
Two types of sensors are available from Hart, and the DewK may be
originally purchased with either one. The high-accuracy sensor
(“H” model) reads temperature to ± 0.125°C over a calibrated range
of 16°C to 24°C. Relative humidity readings are to ± 1.5% RH from
20% RH to 70% RH.
The
standard-accuracy sensor (“S” model) reads temperature to ± 0.25°C
over its calibrated range of 15°C to 35°C. Relative humidity
readings are to ± 2% RH from 20% RH to 70% RH.
All
DewK sensors come with NVLAP accredited certificates of
calibration for both temperature and humidity, complete with data
and NIST traceability. Hart provides exceptional uncertainties,
including total test uncertainty ratios better than 3:1 for both
temperature and relative humidity—even for the high-accuracy
sensors!
Both sensors can also measure temperature below their respective
calibrated ranges to 0°C and above their respective calibrated
ranges to 50°C with typical accuracy of ±0.5°C. And RH readings
from 0% RH to 20% RH and from 70% RH to 100% RH are typically
within ±3%.
Ethernet and Wireless Capability
The DewK gives you all the communications options you expect, and
then some. With its built-in Ethernet RJ45 jack, multiple DewKs
can be monitored from the same screen using our new LogWare III
client-server software. Ethernet also gives you the possibility
for remote connectivity over the internet, so you can monitor
critical conditions while you’re away.
Cables running along the floor can be a safety hazard, and cables
hanging from the ceiling and walls are an eyesore. With the DewK,
your wireless dreams will come true when you connect your computer
through an RF modem up to 100 ft away, without the clutter of all
the extra cables!
Finally, if you need a printout, send data to a printer through
the RS-232 interface in real time.
Math and Statistical Functions
In addition to temperature and humidity, the DewK calculates dew
point, heat index, and rates of change for both temperature and
humidity, without the need to buy additional software. Min, max,
and a variety of other statistics are also calculated and can be
shown on-screen. Daily summary statistics, including min, max,
and maximum rates of change are stored for the most recent sixty
days.
Calibrated Sensors
With the DewK you get two for the price of one. Having inputs for
two sensors, each measuring both temperature and relative
humidity, one DewK can monitor two locations at the same time.
Both sensors can be run via extension cables to remote locations
up to 100 feet away, or one sensor can be directly mounted to the
top of the DewK.
Each sensor is calibrated for both temperature and humidity at
Fluke’s Hart Scientific Division. The calibration constants
assigned to the sensors reside in a memory chip located inside the
sensor housing, so sensors may be used interchangeably between
different DewKs, and the recalibration of sensors doesn’t require
an accompanying DewK.
Sensors may also be assigned a unique identifier (up to 16
characters) to facilitate record keeping by matching the sensor
identifier with the collected data. Each DewK ships with one
sensor, with additional sensors available from Hart. Spare sensors
may also be purchased as a kit, which includes a case for the
sensor, a wall mounting bracket, and a 25-foot extension cable.
Memory
The DewK has enough on-board memory to store up to 400,000 date-
and time-stamped data points. That’s two years’ worth of data for
both measurements from two sensors if readings are taken every ten
minutes!
Alarms and Battery Backup
Alarm settings can be set up quickly in the DewK based on
temperature, the rate of change in temperature, RH, the rate of
change in RH, and instrument fault conditions. Alarms can be both
visual (flashing display) and audible (beeping). Likewise, alarm
settings can be set up and events triggered in LogWare III. The
DewK is also equipped with a 0 to 12 volt alarm output that can
trigger a process control system.
A
backup battery shuts down the DewK’s display but maintains
measurements for up to 16 hours in the event of a power failure.
|
