
USER’S GUIDE
Humidity and Temperature
Data Logger PCE-HT 71N
REC
AL M
PCE Americas Inc.
711 Commerce Way
Suite 8
Jupiter
FL-33458
USA
From outside US: +1
Tel: (561) 320-9162
Fax: (561) 320-9176
info@pce-americas.com
www.pce-instruments.com/english
www.pce-instruments.com
PCE Instruments UK Ltd.
Units 12/13
Southpoint Business Park
Ensign way
Hampshire / Southampton
United Kingdom, SO31 4RF
From outside UK: +44
Tel: (0) 2380 98703 0
Fax: (0) 2380 98703 9
info@pce-instruments.com

INTRODUCTION
Congratulations on your purchase of the humidity
and temperature datalogger. This datalogger module
can be used to monitor humidity and temperature of
greenhouses, warehouses, food transports, aircraft
cabins, refrigerated trucks, containers, museums, and
HVAC equipment. It measures and stores up to
16,000 relative humidity and 16,000 temperature
readings over 0 to 100%RH and -40 to +70°C (-40 to
+158°F) measurement ranges. user can easily set up
the logging rate, high/low alarm and start-mode, and
download the stored data by plugging the module
straight into a PC's USB port and running the
purpose designed software under Windows 98, 2000,
XP, or Vista. Relative humidity, temperature and dew
point (the temperature at which water vapor present
in the air begins to condense) data can then be
graphed, printed and exported to other applications.
The data logger is supplied with a long-life lithium
battery, which can typically allow logging for a year.
Status indication is via flashing Red /Yellow LED and
Green LED.
FEATURES
Memory for 32000 readings(16000 temperature
and 16000 humidity readings)
Dew point indication via Windows Software
Selectable measuring cycle: 2s, 5s, 10s, 30s, 1m,

5m, 10m, 30m, 1hr, 2hr, 3hr, 6hr, 12hr, 24hr
Status Indication via Red/Yellow LED and Green
LED
USB Interface for Set-up and Data Download
User-Programmable Alarm Thresholds for
Relative Humidity and Temperature
Analysis software used to view graph
Multi-mode to start logging
Long battery life
SPECIFICATIONS
* Depending on sample rate, ambient temperature and
humidity and use of alarm LEDs. We recommend that you set
the sample rate more than 5 seconds.
**See below for accuracy graphs.

Figure 1 Relative Humidity Accuracy
Figure 2 Temperature Accuracy
Figure 3 Dew Point Accuracy (at 25OC)
0
10 20
30
40
50
60
70
80
90
100
±0
±2
±3
±4
±5
±1
%RH
¡ãC
±0
±3.6
±5.4
±7.2
±9.0
±1.8
¡ãF
-40
-40
32
0
104
176
40
80
120
±0
±2
±3
±1
248
¡ãC
¡ãF
¡ãC ¡ãC ¡ãC ¡ãC
¡ãF ¡ãF ¡ãF ¡ãF
±0
±3.6
±5.4
±1.8
¡ãF
¡ãC
0
10 20
30
40
50
60
70
80
90 100
±0
±2
±3
±4
±5
±1
%RH
%RH

* To save power, flashing-Cycle can be changed to 20s or 30s
via analysis-software. For more details, please see the guide
of analysis-software.
** To save power, all alarm indications for temperature and
humidity can be disabled. For more details, please
see the guide of analysis-software.
***When both temperature and relative humidity readings
exceed alarm level synchronously, LED status
indication alternate every cycle.
****When battery low, all operations will be disabled
automatically. NOTE: No matter what have data-logging
interrupted any time, you must use the analysis-software to
restart logging.
BATTERY REPLACEMENT
We recommend that you replace the battery every 12
months, or prior to logging critical data.
Datalogger does not lose its stored readings when the
battery is discharged or when the battery is replaced;
the data logging process will however be stopped and
cannot be re-started until the battery has been
replaced and the logged data has been downloaded to
PC.
Only use 3.6V lithium batteries. Before replacing the
battery, remove the model from the PC.
NOTE:
Leaving the model plugged into the USB port for
longer than necessary will cause some of the battery
capacity to be lost.

WARNING: Handle lithium batteries
carefully, observe warnings on battery casing.
Dispose of in accordance with local regulations.
RECONDITION PROCEDURE
Exposure of the internal sensor to chemical vapours
may interfere with the internal sensor and cause
inaccurate readings to be logged. In a clean
environment, this will slowly rectify itself. However,
exposure to extreme conditions or chemical vapours
will require the following reconditioning procedure to
bring the internal sensor back to calibration state.
80°C (176°F) at<5%RH for 36h (baking) followed by
20-30°C (70-90°F) at>74%RH for 48h (re-hydration)
High levels of pollutants may cause permanent
damage to the internal sensor.

DIMENSIONS
(All dimensions in mm)
Int ernal Hum idity and Temperature Sensor Locat ion