ITS Telecom DD890 User manual

Manometer
DD890

2
Introduction
The device measures Gauge/Differential Pressure
from -200 mbar to 200mbar (+-80.29 in H2O), it features
11 selectable units of measure: inH20 , psi , bar , mbar,
kPa , inHg , mmHg ,ozin
2
,ftH20 , cmH20, kgcm
2
.
Additional features include Data Hold. Auto Power Off
disabled , and an USB for capturing reading to a PC
using optional software . Careful use of this meter will
provide years of reliable service.
Specifications
Function
Range
Resolution
Function
Range
Resolution
inH20
80.29
0.01
ozin
2
46.41
0.01
psi
2.901
0.001
ftH20
6.690
0.001
mbar *
200.0
0.01/0.1
cmH20
203.9
0.1
kPa
20.00
0.01
kgcm
2
0.204
0.001
inHg
5.906
0.001
bar
0.200
0.001
mmHg
150.0
0.1
* Resolution: 0.01 mbar < 100 mbar ,0.1mbar>100mbar

3
Display Dual LCD
Accuracy ±0.3%FSO (25
C
o
)
Repeatability ±0.2% (Max.+/ -0.5%
FSO)
Linearity/Hysteresis ±0.29% FSO
Pressure Range

200mbar
Maximum Pressure 500mbar
Response Time 0.5 Seconds typical
Low Battery Indicator Yes
Over range Indicator Err.1
Under range Indicator Err.2
Operating Conditions 0 to 50
C
o
Storage Conditions -10 to 60
C
o
Power Supply 1×9V Battery or
external 9VDC
CP2102 USB to UART Bridge Controller
Serial format: Baud rate: 9600 Baud , 8 Data Bits.

4
Button
The meter has six buttons.
1. UNITS
2. DIF
3. REC
4. HOL D
5. BACKLIGHT
6. ON/OFF
Display Description
1. Hold Function
2. Differential Mode
3. Primary Data screen
4. Record Mode
5. MAX/MIN/AVG
6. Low Battery indicator
7. Pressure Unit indicator
8. Relative Time Clock
9. Data output from USB

5
Operation
1.Power
Press the ON/OFF button to turn power on or off.
The meter will perform a short self-test when turned on.
The meter defaults to the setting used during the last
operation.
2.ZeroAdjust and Offset
Before use and without fittings attached to the
meter, press the HOLD button for more than 2 seconds to
zero the meter .The meter will reset and display“oooo ”
from right to left. 0.000 will be display.
If it is desired to offset the meter and display, press
the DIF button while taking a measurement Subsequent
reading will be the difference between the current
measurement and the measurement that was on the
display when the DIF button was pressed.
4. Data Hold
Press the HOLD button momentarily to freeze the
displayed reading. The ‘HOLD’icon will appear on the
upper left-hand side of the display. If the pressure value
is over the range, error codes will show on the screen.

6
Press the HOLD button again to return to normal
operation.
4.Record
The MAX/MIN mode allows the user to view only
the highest (MAX) , lowest (MIN)or average (AVG)
readings with relative time stamp.
1. Press the REC button once and REC appears on
the display (All other functions are locked out
except for Power & Backlight). The relative time
clock also appears in the secondary display and
starts counting.
2. Press the REC Button again and MAX appears on
the display .The display is now showing the
maximum pressure and relative time that it was
recorded.
3. Press the REC button to display the minimum
MIN reading with the relative time.
4. Press the REC button to display the average value
AVG reading with the relative time.
5. Press the REC button again to continue recording
MAX/MIN /AVG measurements.
6. To exit the MIN/MAX/AVG mode, press the

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REC button for 3 seconds to return to normal
operation.
5.Backlight Display
Press the Backlight button to turn on the
backlight. It will remain on for 40 seconds.
6.Automatic Power Off
The meter will automatically shut off after 20
minutes to conserve battery life. To disable Auto Power
Off , hold down the HOLD button and turn on the meter
on , An “n”will appear in the display indicating that
Auto Power Off mode is disabled. The meter will return
to normal operation when it is turned off.
7.Units
Press the Unit button momentarily and the meter will
cycle through the 11 available units of measure as
indicated by the cursor on the bottom of the display.
USB
The meter has a USB port for use with the optional PC
interface DataAcquisition Software./Hardware kit.
Error Codes
An error message will appear on the display if the
meter fails an internal diagnostic test. And it will freeze
all the buttons.

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1. Err.1: Pressure value is over the range.
2. Err.2: Pressure value is below the range.
3. Err.3: DIF function , the differential pressure value
is over range.
4. Err4: DIF function, the differential pressure value is
below range.
Battery Replacement
When the battery power falls low ,“BAT”will
appear on the LCD. Replace the 9V battery .