Wuntronic COMMETER D3121 User manual

COMMETER D3121
Digital thermometer-hygrometer and datalogger
Instruction manual

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Manual for use of thermometer-hygrometer COMMETER D3121
Instrument is designed for measurement and logging temperature and relative humidity with the
possibility of displaying the dew point temperature. Measured values are displayed on a dual line
LCD display and it is possible to store values into the non volatile memory. Then it is possible to
transfer data to a personal computer. Temperature is measured by RTD sensor Ni1000/6180ppm.
Instrument compares measured values of temperature, humidity and dew point with two adjustable
levels for each measured quantity. Breaking the level is indicated by blinking the proper value on
display and by audio indication (switchable). Instrument is equipped with minimum and maximum
memory and Hold function. Minimum and maximum values and Hold value are possible to display
on the LCD anytime.
Technical parameters:
Parameters of measurement:
Temperature:
Range of measurement: -30 to +105 °C (temperature from +85 to +105°C with the
limitation accordingly to the graph below)
Resolution: 0.1 °C
Accuracy: ±0.4 °C
Humidity: Range measurement: 0 to 100 %RH
Resolution: 0.1 %RH
Accuracy: ±2.5 % RH at the range of 5 to 95 %RH at 23°C
Dew point temperature (calculated from temperature and humidity):
Range: -50 to +80 °C
Resolution: 0.1 °C
Accuracy: ±0.5 °C at the range of 30 to 95 % RH
Response time with stainless sensor cover (air flow approximately 1 m/s):
air temperature: t90 < 75 s (temperature step 20 °C)
relative humidity: t90 < 60 s (humidity step 30 %RH, constant temperature)
Measuring interval a display reading refresh: approximately 0.7 s in FAST mode
0.7 to 5 s in dynamic mode
Logging interval (only in automatic logging mode): 10 s to 24 h
Memory capacity: for manual logging 1000 sets of all input quantities
for non cyclic automatic logging total 8124 values
for cyclic automatic logging total 7644 values
The above specified numbers are maximum possible. Capacity is slightly lower if logging
was interrupted by communication with computer, by stopping logging or switching OFF
the instrument
Communication with computer: RS232 (serial port)
Real time clock: adjustable from computer, integrated calendar including leap years
Power: battery 9V or ac/dc adapter 12V with NiCd accumulator 9V
Average current consumption: 0.15 to 0.7 mA (depending on operation mode)
Operation conditions:
Ambient temperature range: -10 to +60 °C
Ambient relative humidity range: 5 to 95 %RH non condensing, probe 0 to 100% RH
Outer characteristics in accordance with EN 33-2000-3: normal environment with
characteristics AD1, AE1, AF1, AG1, AH1, AK1, AL1, AN1, AP1, AQ1, AR1, AS1,
BA1, BE1
Not allowed manipulation: it is not allowed to touch sensors under the cover to avoid
sensors damaging or to effect calibration.
Dimensions: 141 x 71 x 27 mm
Weight including battery: approximately 150 g

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Battery life depends on selected display refresh mode (see below). In FAST mode display is
refreshed in shortest possible interval with highest current consumption. In dynamic mode display
is refreshed in interval up to 5 s in case measured values remain stable. Refresh interval is shortened
to approximately 0.7 s only if measured values change. Current consumption in this mode in usual
operation is lower, battery life is up to 4 times longer. The FAST mode is recommend to use only in
cases, when slower display response is not acceptable.
Battery voltage drop below 7 V is indicated with blinking of "BAT" in default display mode
(displaying of actual values) and FAST mode is automatically cancelled to save the battery. At the
same time audio indication of alarms is automatically switched OFF.
If instrument is supplied from external ac/dc adapter, internal 9V battery should be replaced with
rechargeable NiCd accumulator. In usual operation from adapter accumulator is charged only with
small current. If accumulator is totally discharged, its full charging in instrument takes
approximately 100 hours. Instrument with accumulator is not recommended for permanent
operation without ac/dc adapter plugged. Accumulator works only as a standby source in case of
power mains failure.
Switching ON and OFF the instrument
Switch ON the instrument by pressing ON/OFF key. After switching ON
the instrument all symbols on the LCD are displayed. If the ON/OFF key is
being held pressed, all LCD symbols are displayed till the key is released.
In usual operation instrument then starts the measurement mode and actual
measured values are displayed.
If a voltage drop below critical limit occurred since last adjustment of
internal real time clock or battery disconnection longer than approximately
1 min, new instrument initialisation is performed (reading INIT could be
displayed up to 12 s !).
After initialisation is finished instrument starts to display internal time to
warn to incorrect internal time. New time adjustment is performed by the
computer. Press MENU key to switch instrument to actual measurement
mode.
It is possible to switch OFF the instrument anytime, all instrument setting is kept saved. If

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automatic logging was active before instrument is switched OFF, logging will continue with the
same parameters after new switching ON.

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Displaying of actual measured values
In this mode is instrument anytime after switching ON. It is possible to enter this mode from other
modes by pressing or by repeating pressing of MENU key.
Temperature in °C is displayed on the upper LCD line and relative humidity
in %RH is displayed on the lower LCD line.
Press DISPLAY key to display other readings - temperature in °C on upper
line and dew point temperature on lower line (°C DP).
Function HOLD (storing of actual measured values) and minimum a maximum memory
Press HOLD key in the default mode (displaying of actual measured value) to store actual
measured values to internal memory (indicated by short beep). Anytime it is possible to display
stored values from MENU (see below). Each pressing of the HOLD key in the default mode causes
values stored in HOLD memory are replaced with actual ones.
Switched ON instrument permanently updates minimum and maximum
memory of each measured values. Press MIN key (resp. MAX key) in the
default mode to display minimum (resp. maximum) reading. These
minimum and maximum readings are indicated by MIN (MAX) symbols on
the LCD. Press DISPLAY key to display minimum (resp. maximum) value
of other values. Pressing MIN (MAX) or MENU key again to return to
default mode. Minimum and maximum memory is cleared from menu after
confirmation selection CLR (see below). Values in HOLD, MIN and MAX
memories remain stored even after instrument is switched OFF.
Functions and settings available from menu
Press MENU key to enter mode of viewing menu items one by one. Press arrow keys up and
down to list all menu items. Press MENU key again to return to default mode (displaying of actual
measured values).
First selection is START/STOP logging. There are two possibilities: if
logging is stopped, logging start is offered (symbol Strt = START), if
logging is in progress already, logging stop is offered (reading STOP). Press
ENTER key to confirm one of two possibilities. Notice: if battery voltage is
low it is not possible to start logging.
Press ENTER key to enter alarm setting mode (see below).
This item indicates if audio signaling of alarm indication is switched on
(On) or switched off (OFF). Press ENTER key to change actual setting.

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Notice: if the battery voltage is low, audio indication is out of operation to
reduce current consumption independently on this selection.
Clearing of minimum and maximum memory of all values. Memory is
cleared after pressing ENTER key. Clearing is confirmed by reading YES
on the LCD lower display.
Press ENTER key to display values stored in the HOLD memory. Press
DISPLAY key to display other stored values (dew point temperature). Press
MENU key to leave this mode.
Time (hour and minute) in internal real time clock of the instrument. Press
ENTER key to check date (day, month, year).
Battery voltage of partially loaded battery is displayed. This value illustrates
battery condition.
Display refresh mode is indicated. In the FAST mode refreshment is fastest
with regular interval approximately 0.7 s. In the dynamic refresh mode
(DYN.) each 15 s refresh interval of display is doubled to maximum 5 s if
measured values are stable. If measured values change, refresh interval
decreases to approximately 0.7 s. This dynamic mode prolongs battery life
significantly. Select the desired mode by ENTER key. Notice: if battery
voltage is low, the FAST mode is out of operation to reduce current
consumption independently on this selection.
Each pressing of ENTER key causes displaying information on storing
interval, actual logging mode (MODE), memory occupation (MEMO - in
automatic logging mode memory occupation in % is displayed, in manual
mode the number of logged values is displayed) and service information on
software version (upper LCD line) together with instrument configuration
on the LCD lower line.

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Alarm indication and setting
It is possible to set lower and upper limit for each measured quantity.
Breaking of the limit is indicated by blinking of the appropriate value on the
display. If a new alarm was indicated (i.e. it was not active in the previous
measurement), display starts to display the value out of limits. If at least one
alarm is active, audio indication can be activated, if menu AUDI "On" is
selected (see setting described above). Alarm activation of each value can
be disabled by setting lower alarm limit of the desired value up to its
maximum. This is indicated by OFF reading at the position of numeric
value. Value of upper limit of the same alarm is indifferent.
To set alarms press MENU key, select ALAR from menu items and confirm
by pressing ENTER key.
Reading ALLO indicates adjusted lower alarm limit (here air temperature).
Set the desired value by means of the arrow keys. Press and hold the arrow
key UP to make value increase fast. Press and hold the arrow key DOWN to
make value decrease fast. Release the arrow key and press ENTER to
confirm new limit
Reading ALHI indicates adjusted upper limit of the same alarm (here air
temperature). Set the desired value in the same way as in above lower limit.
If needed it is possible to get back to lower limit setting of the same alarm
by pressing DISPLAY key. Press ENTER key to confirm new upper limit.
Then you are offered to set alarm of other input value (here relative
humidity). The procedure is the same as the above temperature limit setting.
Alarm activation of each value can be disabled by setting lower alarm limit
of the desired value up to its maximum. This is indicated by OFF reading at
the position of numeric value. Value of upper limit of the same alarm is
indifferent.
It is possible to leave the alarm setting mode by pressing MENU key. New
adjusted limits up to pressing MENU key are stored in memory.
After pressing ENTER key it is possible to set alarm limits for dew point
temperature.

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Logging mode
In logging mode measured values are stored to instrument internal memory. Memory is non
volatile, i.e. if battery voltage drops or battery is disconnected, stored data will not be lost.
Instrument can work in two logging modes:
automatic mode - actual measured values are stored to memory in adjustable time interval. Storing
of the first value is synchronised with internal real time clock , so the memorizing is performed
at sharp multiples of minutes, hours and days. E.g. if the storing interval is 15 minutes value will
be stored each 15., 30., 45. a 00. minute and zero second in each hour, if interval is 3 hours
values will be stored in 00:00:00, 03:00:00, 06:00:00. etc. It means after starting automatic
logging instrument waits for the nearest integer multiple of time and then stores the first value.
manual mode - actual measured value is stored after pressing ENTER key (instrument should be in
default mode of displaying actual measured values). Each storing is indicated by a short beep and
position of the record in memory is displayed (reading MEMO with the record serial number). In
this mode it is possible to store max. 1000 set of records.
It is possible to select one of the three logging modes (MODE):
- automatic non cyclic logging, when logging stops after fulfilling the memory. Reading MEMO
FULL is displayed (reading disappears after pressing any key)
- automatic cyclic logging, when after fulfilling the memory oldest data are replaced with new
values
- manual logging, designed for manual storing of measured values by ENTER key
Logging modes are not mutually compatible and after changing logging mode memory of the
instrument should be cleared.
Logging in progress will always be interrupted by instrument connection to the computer or
switching OFF the instrument by ON/OFF key. Logging in progress will be automatically stopped
if battery voltage below 7 V is indicated by the instrument. This prevents to log values effected by
low battery voltage.
Logging start from instrument keyboard
Start logging by confirmation of the menu item START (symbol Strt) by
pressing ENTER key.
Notice: it is not possible to start logging if low battery voltage is indicated.
Instrument offers the possibility to clearing the instrument memory (ERAS).
If you do not wish to clear the memory before new logging start, confirm
selection ERAS NO by pressing the ENTER key
Now instrument displays adjusted storing interval. To modify the storing
interval use arrow keys. Interval 10 sec is displayed as MIN 0:10, minute
intervals are displayed as MIN x:00 and hour intervals as x:Ho. Confirm
adjusted interval by pressing ENTER key. Notice: if manual logging mode
is selected, this menu item is skipped (there is no interval adjustment).
Logging is started and instrument returns to default mode displaying actual
values. Logging in progress is in default mode indicated with reading LOG
on display. If memory is filled over 90 %, symbol LOG is blinking (only in
automatic logging).

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Logging start with clearing memory and logging mode selection
It is possible to clear memory only if logging is stopped. Modification of logging mode is
enabled only after memory is cleared. Clearing of memory is optional part of the above procedure
logging START. Notice: there is no way to "undelete" the cleared data!
If it is needed to clear the memory before logging start, first it is necessary
to select menu item logging START (symbol Strt) and confirm by pressing
ENTER key.
Notice: if low battery voltage is indicated, it is not enabled to start logging
nor to clear the memory
Now instrument offers possibility to clear the memory (ERAS). Default is
selection ERAS NO. If clearing of the memory is needed use the arrow keys
to select ERAS YES and confirm by pressing ENTER key..
Clearing procedure is in progress. It takes approximately 16 s and the
duration is indicated by displaying of already cleared memory in % (digits 0
to 100).
After memory is cleared it is possible to select one of three logging modes
(MODE) by using arrow keys (non cyclic logging is indicated by symbol
n.CYC, cyclic logging by symbol CYCL and manual logging by symbol
Man). If manual logging mode is selected, after confirmation by ENTER
key logging is active. In automatic logging mode (i.e. cyclic or non cyclic)
last applied storing interval is offered to confirm or modify. See above
procedure.
Logging stop from keyboard
Logging stop is enabled by confirmation of menu item STOP by pressing
ENTER key.
Reading STOP NO is displayed to enable logging stop. Use arrow keys to
modify to STOP YES. Logging is still in progress.
Logging is stopped after confirmation selection STOP YES by pressing
ENTER key. Instrument then returns to default mode of displaying actual
values.

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Connection of the instrument to a personal computer
For connection of the instrument to a personal computer is designed the communication cable
(included in delivery). Connect the cable with 9pin connector Canon to computer serial port
(COM1 or COM2). Connect cable other side (JACK 3.5mm) to the instrument. During time
instrument is connected to the computer, there is a reading PC on the LCD display and
measurement nor logging is interrupted. Keyboard of the instrument is disabled with the exception
of ON/OFF key.
Result of reading data to the computer is a protocol of measurement including instrument serial
number and a table of logged values with date and time.
After disconnection of the communication cable reading PC disappears and instrument is in the
default mode as after switching on by the ON/OFF key. If logging was in progress before
connection to the computer, logging will continue with the same parameters after disconnection of
the cable (if new setting of logging was not performed during communication - including logging
stop).
The most power from the battery is needed during communication with the PC - let the
communication cable plugged-in the instrument only for time necessary for data transfer! If
you let instrument plugged-in the computer longer than approximately 5 minutes with no
communication, instrument will be automatically switched OFF.
Battery replacement
If battery voltage is low logging mode of the instrument is disabled. Low battery voltage is
indicated on the display with blinking reading "BAT". It is necessary to replace it with new one as
soon as possible. Battery is located under small cover on the instrument lower side. It is absolutely
necessary to replace battery with instrument switched OFF, otherwise internal time and setting of
d.REF. and AUDI (from menu selections) and data in memory HOLD, MIN and MAX will be lost.
For the same reason do not disconnect the battery for longer than 1 minute even if instrument is
switched OFF. If it happens (or if battery is totally discharged), it is necessary to set time from the
computer and in appropriate menu selection set again LCD refreshment mode (d.REF.), alarm audio
indication (AUDI) and clear the minimum and maximum memory (CLR).