Technical Data
1620A “DewK”
Thermo-Hygrometer
The Fluke MET/CAL compatible
1620A DewK Thermo-Hygrometer
revolutionizes environmental mon-
itoring for calibration laboratories.
Now you can easily monitor
and record conditions through-
out your entire facility with the
DewK’s new Ethernet and wire-
less connections, and set your
upgraded LogWare III software to
notify you immediately of chang-
ing conditions.
You’ll still have the superior
convenience, dependability, and
NIST-traceable accuracy of a 1620,
but your 1620A will give you the
added accessibility and peace of
mind you’ve been looking for.
• Superioraccuracy
• Networkenabled
• Powerfulloggingandanalysistools
• Twointerchangeablecalibratedsensors
• Hugememory
• Upgradedsoftware
including total test uncertainty
ratios better than 3:1 for both
temperature and relative humid-
ity—even for the high-accuracy
sensors!
Both sensors can also measure
temperature below their respec-
tive calibrated ranges to 0 °C and
above their respective calibrated
ranges to 50 °C with typical accu-
racy 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 com-
munications 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. Ether-
net 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.
Accuracy
Two types of sensors are avail-
able from Fluke Calibration, 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 humid-
ity 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. Fluke pro-
vides exceptional uncertainties,
2 Fluke Calibration 1620A “DewK” Thermo-Hygrometer
Calibrated sensors
With the DewK you get two for
the price of one. Having inputs for
two sensors, each measuring both
temperature and relative humid-
ity, 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 humid-
ity. 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 recali-
bration 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 Fluke. 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.
The DewK lets you view data just about any way you like it. Both graphical data and statistical data can be shown for temperature and humidity from
one or two inputs. Modifying any of the standard screens is easily done, so you see exactly what you want—no more, no less.
One very cool display
Want to view data from across
the room? Want to view data from
two temperature and two humid-
ity inputs simultaneously? Want
to view data graphically, statisti-
cally, or both? At the same time?!
The DewK does everything you
could want—or at least everything
we could think of. Up to sixteen
different display setups can be
stored and recalled at the touch of
a single button. And all 16 can be
easily modified, so you get exactly
what you want.
Confidence
Fluke Calibration supplies the
world’s finest measurement
laboratories with world-class
temperature standards. We not
only measure temperature and
humidity better than anybody, we
make temperature measurements
functional and productive.
Don’t compromise on your
lab standards. Measure with
confidence. Partner with Fluke
Calibration.
3 Fluke Calibration 1620A “DewK” Thermo-Hygrometer
If you really want to get the most
out of your DewK, LogWare III is
an investment worth every penny.
As client-server or stand-alone
software, it remotely monitors and
logs an unlimited number of con-
current log sessions into a single
database. That means data from
many DewKs can be managed in
real time via Ethernet, RS-232, or
wireless connections.
LogWare III allows you to
customize your graph trace color,
alarms, and statistics as you go.
You can start/stop log sessions
and modify sample intervals
from your computer. LogWare III
supports “hot-swapping,” which
allows you to remove and replace
sensors without shutting down
the log session. LogWare III also
supports security features such as
passwords for individual users or
groups/teams, a built-in admin-
istrator account, pre-defined
user groups, and customizable
permissions.
Never again be the last to
know about a problem. Custom-
izable email settings allow you
to send emails to designated
recipients, including cell phones
and PDA’s, when a log session
begins, ends, or is aborted; when
the DewK’s battery is low; when a
sensor calibration is due; or when
a temperature/humidity alarm is
exceeded.
If you cannot be reached via
email, you can always arrange to
be paged instead. Data stored on
the DewK can be imported into
the software, which is a handy
feature when power outages dis-
able the network.
Are you ready for a deep dive
into your data? Historical data can
be viewed by sensor (model/serial
number) location, or log session
and displayed in a spreadsheet-
style grid. Logged data can also
be exported to HTML, RTF or
ASCII text for use in your ana-
lytical software, or simply print
historical data and graphics.
Customizable graphs in
LogWare III with zooming
capability are an easy way to
analyze your data history, and
data points that need to be
explained can be highlighted,
annotated, and referred to later.
LogWare III statistics include
min, max, spread, average, and
standard deviation functions,
and printed reports keep track of
the number of temperature and
humidity measurements that were
found to be out of tolerance.
LogWare III
Ordering Information
Models
1621A-H The “DewK” Thermo-Hygrometer,
High-Accuracy Value Kit (includes two
high-accuracy sensors, wall mount
bracket, RS-232 cable, 7.6 m [25 ft]
sensor extension cable, sensor wall
mount bracket, sensor case, and 9936A
LogWare III single-PC license)
1620A-H The “DewK” Thermo-Hygrometer,
High-Accuracy (includes one high-
accuracy sensor, wall mount bracket,
and RS-232 cable)
1621A-S The “DewK” Thermo-Hygrometer,
Standard-Accuracy Value Kit (includes
two standard-accuracy sensors, wall
mount bracket, RS-232 cable, 7.6 m [25
ft] sensor extension cable, sensor wall
mount bracket, sensor case, and 9936A
LogWare III single-PC license)
1620A-S The “DewK” Thermo-Hygrometer,
Standard-Accuracy (includes one
standard-accuracy sensor, wall mount
bracket, and RS-232 cable)
Sensors
2626-H Spare Sensor, high-accuracy
2627-H Spare Sensor Kit (includes high-accu-
racy sensor, sensor case, sensor wall
mount bracket, and 7.6 m [25 ft] exten-
sion cable)
2626-S Spare Sensor, standard-accuracy
2627-S Spare Sensor Kit, (includes standard-
accuracy sensor, sensor case, sensor
wall mount bracket, and 7.6 m [25 ft]
extension cable)
Accessories
2633-RF Wireless Option (requires wireless
modem)
2633-USB Wireless Modem, USB to wireless
2633-232 Wireless Modem, RS-232 to wireless
2628 Cable, Sensor Extension, 7.6 m (25 ft)
2629 Cable, Sensor Extension, 15.2 m (50 ft)
9328 Protective Case for 1620A and two
sensors
2607 Protective Case for spare sensor
2361 Spare Power Supply, 100 to 240 V ac
Software
9936A LogWare III Software (Single License)
9936A-L1 1-Pack License, LogWare III Software
9936A-L5 5-Pack License, LogWare III Software
9936A-L10 10-Pack License, LogWare III Software
9936A-LST Site License, LogWare III Software
9936A-UPG 9936A Software Upgrade from version
1.x
4 Fluke Calibration 1620A “DewK” Thermo-Hygrometer
Specifications
Operating range 0 °C to 50 °C (32 °F to 122 °F); 0 % RH to 100 % RH
Calibrated temperature
Accuracy (“H” Model)
± 0.125 °C from 16 °C to 24 °C (± 0.225 °F from 60.8 °F to 75.2 °F)
Calibrated temperature
Accuracy (“S” Model)
± 0.25 °C from 15 °C to 35 °C (± 0.45 °F from 59 °F to 95 °F)
Calibrated RH accuracy
(“H” Model)
± 1.5 % RH from 20 % RH to 70 % RH
Calibrated RH accuracy
(“S” Model)
± 2 % RH from 20 % RH to 70 % RH
Expected extrapolated
Performance (uncertified)
± 0.5 °C (± 0.9 °F) outside calibrated range, ± 3 % RH outside calibrated range
Delta temperature accuracy ± 0.025 °C for ± 1 ° changes within 15 °C to 35 °C (± 0.045 °F for ± 1 ° changes within 59 °F to 95 °F)
Temperature resolution User selectable up to 0.001 °C/°F on front-panel display (0.01° recorded)
Delta humidity accuracy ± 1.0 % RH for ± 5 % changes within 20 % RH to 70 % RH
RH resolution User selectable up to 0.01 % on front-panel display (0.1 % recorded)
Inputs Up to two sensors, measure temperature and relative humidity, detachable, cable-extendable,
interchangeable, self-contained calibrations, may be assigned unique 16-character identifications
Display 240 x 128 graphics monochrome LCD, displays password-protected temperature/humidity data graphically,
numerically, and statistically (one or both channels); 16 pre-defined, user-changeable screen setups
Memory 400,000 typical individual date/time-stamped readings
Alarms Password-protected visual, audible, and external alarms for temperature, temperature rate, RH, RH rate, and
fault conditions
Alarm port output 2.5 mm two-conductor subminiature plug, 0 V normal, 11 to 12 V active, sources up to 20 mA
Connectivity Ethernet, RS-232, RF (optional)
Ethernet RJ45 jack, 10 Base-T or 100 Base-TX; static or dynamic (DHCP client) IP address assignment
Web page Embedded web page interface features: instrument identification, measurements, password-protected
terminal page; can be disabled
Wireless option Requires wireless modem. 802.15.4 (underlies Zigbee), 2.4 GHz frequency, 1 mW transmit power, 30 m
(100 ft) typical unobstructed range; can be disabled
Mounting Wall mounted (hardware included) or set on a bench top
Power 12 V dc from external 100 to 240 V dc power supply
Battery backup Standard 9 V battery enables continued measuring during power disruptions
Size (DewK) (HxWxD) 125 mm x 211 mm x 51 mm (4.9 in x 8.3 in x 2.0 in)
Size (Sensors) (LxDia) 79 mm x 19 mm (3.1 in x 0.75 in)
Weight 0.7 kg (1.5 lb)
Calibration Certificate of NIST-traceable NVLAP accredited temperature and humidity calibration included; As Found
and As Left data supplied at three temperature points and three humidity points each at 20 °C (68 °F);
Complies with NCSL/ISO/IEC 17025:2000 and ANSI/NCSL Z540-1-1994
LogWare III (optional software) Requirements include: Microsoft® Windows® 2000 (SP4) or XP (SP2) operating system, IBM compatible Intel
Pentium® IV 1 GHz PC processor or better, 512 Mb RAM (1 Gb or more recommended), 200 Mb HDD space
for installation (additional free space recommended for data storage), CD-ROM drive for installation
Fluke Calibration
PO Box 9090,
Everett, WA 98206 U.S.A.
Fluke Europe B.V.
PO Box 1186, 5602 BD
Eindhoven, The Netherlands
For more information call:
In the U.S.A. (877) 355-3225 or Fax (425) 446-5116
In Europe/M-East/Africa +31 (0) 40 2675 200 or Fax +31 (0) 40 2675 222
In Canada (800)-36-FLUKE or Fax (905) 890-6866
From other countries +1 (425) 446-5500 or Fax +1 (425) 446-5116
Web access: http://www.fluke.com
©2008-2011 Fluke Corporation. Specifications subject to change without notice.
Printed in U.S.A. 2/2011 3397500B D-EN-N
Modification of this document is not permitted without written permission from Fluke Corporation.
Fluke Calibration. Precision, performance, confidence.™
