Keller DCX Series User manual
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keller-druck.com
November 2013
OPERATING INSTRUCTIONSOPERATING INSTRUCTIONS
DCX DATA LOGGERDCX DATA LOGGER
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Table of contents
Product overview 3
Overview of structural designs, Series DCX 4
Measuring principle for Series DCX 5
General
Level measurement
Relative pressure measurement (VG)
Absolute pressure measurement (SG)
Absolute/absolute pressure measurement (A/A)
Level measurements in closed receptacles
Functionality of the Series DCX data logger 8
Data memory
Installation instructions 9
Important information
Guidelines on safe and efcient use
Warranty conditions
Data for repair and replacement
Disposal of old electrical equipment and batteries / rechargeable batteries
Fitting instructions 11
Requirements for the location
Installation in level tubes
Water level conguration
Installation of relative data logger (-VG versions)
Conguring and reading the DCX
DCX time
Verifying measured data
Device memory
Maintenance 16
Battery
Changing the battery, Series DCX
Watertightness
Rechargeable battery
Ventilation diaphragm
Moisture absorber cartridge
Cleaning 19
Cleaning the level sensor
Cleaning the air pressure sensor (-AA versions)
Calibration 20
Setting the zero point
Testing by the manufacturer
Level measurement with pressure sensors 20
Overview of DCX 22
Accessories 26
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Product overview
The data loggers in Series DCX are autonomous, battery-powered data collectors
which can measure the water level (water column, i.e. pressure) and temperature over
lengthy periods.
Series DCX is designed for level measurements and is generally used for long-term
data acquisition in applications with brackish water, salt water or fresh water.
Series DCX is also available with a connecting thread for process applications.
Various versions are available in Series DCX. The standard material is stainless steel,
316L (DIN 1.4435). For added resistance to media, the logger can be manufactured to
order from Hastelloy or titanium as options. The key distinguishing features of products in
Series DCX are their measuring methods and the diameter of the probe.
Designation Measuring
principle
Max.
pressure range Max. mH2O
Max. cable length**
DCX-16 absolute 0,8…11 bar abs.
0…100 mH2O
–
DCX-16 VG relative 0…10 bar rel.
0…100 mH2O
500 meters
DCX-16 SG absolute 0,8…11 bar abs.
0…100 mH2O
500 meters
DCX-18 absolute 0,8…11 bar abs.
0…100 mH2O
–
DCX-18 VG relative 0…10 bar rel.
0…100 mH2O
500 meters
DCX-18 SG absolute 0,8…11 bar abs.
0…100 mH2O
500 meters
DCX-22 absolute 0,8…11 bar abs.
0…100 mH2O
–
DCX-22 Baro absolute 0,8…1.3 bar abs.
0…100 mH2O
–
DCX-22 VG relative 0…10 bar rel.
0…100 mH2O
500 meters
DCX-22 SG absolute 0,8…11 bar abs.
0…100 mH2O
500 meters
DCX-22 AA
absolute/absolute
0,8…11 bar abs.
0…100 mH2O
80 meters
DCX-25 PVDF absolute 0,8…11 bar abs.
0…100 mH2O
–
DCX-38 VG relative 0…
300 mbar rel. 0…3 mH2O
500 meters
DCX-22 AA
Probe diameter
16 = Ø 16 mm
18 = Ø 18 mm
22 = Ø 22 mm
25 = Ø 25 mm
38 = Ø 38 mm
Version
.... Absolute pressure measurement / without cable
VG Relative pressure measurement / with cable
SG Absolute pressure measurement / with cable
AA Absolute pressure measurement with 2 sensors / with cable
PVDF For use in aggressive media.
Special housing made of polyvinylidene uoride (PVDF) with high
resistance to chemicals / Available for probe diameter of 25 mm,
without cable only
** For other system lengths, please contact our sales staff
Maximum pressure ranges and cable lengths
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Overview of structural designs, Series DCX
-VG -SG
-VG -SG
-VG -SG -AA
Different versions of the autonomous data loggers in Series DCX are available from
KELLER in order to meet the requirements for the measuring point, the on-site environ-
mental conditions and the uid to be measured:
Series DCX-16
- probe diameter 16 mm
Series DCX-18
- probe diameter 18 mm
- powered by rechargeable battery
- completely welded in
- screw-on cable
Series DCX-22
- probe diameter 22 mm
- AA version
- high-accuracy version
- customized versions
on request
Series DCX-25 PVDF
- probe diameter 25 mm
- for use in aggressive media
Special housing made of polyvinylidene uoride (PVDF)
with high resistance to chemicals. Pressure sensor in
Hastelloy or titanium, according to choice
Series DCX-38 VG
- probe diameter 38 mm
- to measure low pressures or
levels (measuring ranges: 0,5 / 1 / 3 mWS)
- capacitive measuring cell with gold-plated
ceramic diaphragm
- Moisture absorber cartridge included in scope of delivery
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Measuring principle for Series DCX
DCX-
①
Cable
Cable with integrated
capillary tube
Surface of
water
① ① ①
②
③
-AA version -VG version -SG version
①Level sensor
P1 = medium pressure [bar]
TOB1 = medium temperature [°C]
②Air pressure sensor
P2 = air pressure [bar]
TOB2 = air temperature [°C]
③Reference aperture
For physical compensation
of the ambient pressure (air pressure)
optional
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General information
Fluctuations in the groundwater level (or the levels of other uids) can be determined
and located precisely by measuring the prevailing (hydrostatic) pressure at a dened
depth below the surface of the water. To convert the pressure [bar] into the water
column level [mWS], it is only necessary to know the density of the uid.
Example pure water (H2O): 100 mbar ≈ 1,02 mWS
p = hydrostatic pressure (0,1 bar = 10,000 N/m
2
)
ρ = density (kg/m
3
)
g = gravitational acceleration (m/s
2
)
h = height of water column (m)
Level measurement
In open systems, i.e. with the classical method of measuring
the lling level, the difference between the pressure acting
on the level sensor (total pressure) and the ambient pressure
acting on the water (air/atmospheric pressure in most cases) is
always measured. The pressure difference determined in this
way corresponds to the hydrostatic water pressure.
As a result of this measurement method, the level measurement becomes independent
of weather-induced uctuations in air pressure that act on the surface of the uid. The
following methods of compensating for air pressure are available:
Relative measurement method (VG)
In the relative measurement method, the sensor cable has an integrated capillary tube
which provides the reference to the ambient air pressure directly on the level sensor.
The sensor pressure measured in this way is therefore physically compensated for air
pressure.
Advantage: high accuracy and resolution
Disadvantage: high ambient humidity at the measuring point may disrupt or interrupt
compensation for air pressure and, in extreme cases, may even damage
the level sensor (
→
use moisture absorber cartridges)
Ambient pressure (Air pressure)
Hydrostatic pressure
of the water
Total pressure
h = p =N/m
2
=mWS
ρ
*
g kg/m
3
*
m/s
2
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Absolute measurement method (SG)
With the absolute measurement method, the prevailing total pressure on the level sen-
sor is determined (= air pressure + hydrostatic water pressure). To compensate for
the inuence of uctuations in air pressure, a second data logger is positioned on the
surface as a barometer.
Advantage: very robust, impervious to ambient humidity
Disadvantage: no integrated air pressure compensation
Absolute/absolute measurement method (A/A)
Total pressure and air pressure are each determined by means of a pressure sensor
(A/A technology) and are calculated mathematically in the device by subtracting the two
measured values. A sensor cable without a capillary tube is used for this measurement
method, and this is why AA systems are highly resistant to the ambient humidity prevail-
ing at the measuring point.
Advantage: very robust, impervious to humidity or ooding
Disadvantage: slight reduction in measurement accuracy because of measurements
by two sensors
Level measurements in closed receptacles
For level measurement in closed receptacles/vessels,
the internal pressure in the vessel is measured instead of
the air pressure. The A/A measurement method is usually
selected on account of the humidity prevailing inside the
vessel.
Air pressure
Internal
pressure
Water
pressure
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Functionality of Series DCX
Autonomous data loggers in Series DCX record the values measured for pressure and
temperature together with the time of each measurement.
The following types of recording and initial conditions are supported:
Recording interval Constant
storage interval
Interval ≥ 1 second
Event-controlled
recording
If value is exceeded
If value is undercut
If value changes
Initial conditions Directly after programming is completed
Specied, user-dened time
Recording starts when a value has been undercut
Recording starts when a value has been exceeded
→Constant storage interval and event-controlled recording can be used simultaneously
Data memory
The following table gives an overview of recording periods for various constant
measurement intervals. (Data memory size: 2 Mbit)
Type Interval Number of
channels
Measurement channel Recording period
DCX-22 1 sec 1 Total pressure > 15 h 54 min
DCX-22 1 min 1 Total pressure > 21 h 7 h
DCX-22 1 h 1 Total pressure > 3 y 6 m
DCX-22 1 sec 2
Total pressure and medium temperature
> 7 h 57 min
DCX-22 1 min 2
Total pressure and medium temperature
> 14 d 4 h
DCX-22 1 h 2
Total pressure and medium temperature
> 2 y 4 m
DCX-22 1 d 2
Total pressure and medium temperature
> 56 y 9 m
DCX-22AA 1 sec 5Air pressure and air temperature,
total pressure and medium tempera-
ture, calculated water column level
> 3 h 10 min
DCX-22AA 1 min 5Air pressure and air temperature,
total pressure and medium tempera-
ture, calculated water column level
> 7 d 2 h
DCX-22AA 1 h 5Air pressure and air temperature,
total pressure and medium tempera-
ture, calculated water column level
> 1 y 2 m
DCX-22AA 1 d 5Air pressure and air temperature,
total pressure and medium tempera-
ture, calculated water column level
> 28 y 4 m
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Installation instructions
Important information
KELLER website
At www.keller-druck.com, you will nd a software section where you can download
all KELLER’s software programs free of charge. The site contains the latest software
versions together with datasheets and operating instructions for the corresponding
products.
Service and Support
For service and support, please contact your local dealer or contact us at www.keller-
druck.com
Guidelines on safe and efcient use
• Treat the product with care and keep it in a clean place that is free of dust.
• This product must only be used within the specied temperature range
(
→
Product datasheet)
• Do not drop or throw the device
• Do not attempt to modify the device
• The sensor pressure diaphragm is sensitive to contact. Do not press the diaphragm in
by hand or damage it with sharp objects. Do not direct water jets at the diaphragm.
• Only use this device for non-ammable uids with no explosion hazard. KELLER
offers a series of measurement equipment products suitable for use in areas with
explosion hazards (ATEX zones). For more information, please contact our sales
staff.
•
Aggressive media may damage the product. Make sure that the materials in the product
are not attacked by the medium to be measured.
• With relative versions (VG), the end of the cable must be located in a dry environment
in order to prevent condensation forming. If the cable ends in a humid environment, it
is highly advisable to use moisture absorber cartridges.
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• The level measurement sensor must not freeze up in the medium
• Do not glue, block or contaminate any ventilation components as this will substantially
impair measurement accuracy.
• Fasten/secure the product so that the logger cannot fall into the measuring point in
case of a handling error.
Warranty conditions
The warranty does not apply to faults on the device caused by normal wear, incorrect
use or misuse, or failure to comply with KELLER’s instructions.
Data security
KELLER assumes no responsibility for data loss of any nature, and shall not pay com-
pensatory damages in case of data loss. Data stored in the product may be lost if the
product is repaired or replaced. You should always create a backup of all data stored in
the product before releasing it for repair or replacement.
Disposal of old electrical equipment and batteries / rechargeable batteries
To prevent possible damage to the environment or to health due to uncontrolled waste
disposal, this product must be separated from other waste and recycled correctly in
order to ensure sustainable use of the raw materials. Remove rechargeable
batteries that have been installed permanently. Permanently installed rechargeable bat-
teries must be removed only by a waste processing facility or a trained service techni-
cian.
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Fitting instructions
Requirements for the location
The DCX logger unit is installed in a stable position at the measurement location
in order to record a groundwater level.
• If the logger is fully sunk into the ground (e.g. in a sewer shaft), free movement of
the water level in the tube must be ensured by above-ground openings (ventila-
tion apertures)
• Lateral movements of the level sensor may cause measuring errors or cable
breaks. For these reasons, t the level sensor in a calm zone or in a suitable
protective tube
• On VG versions, the sensor cable contains a capillary tube to compensate for
atmospheric pressure. Therefore, position the cable end of VG versions in a dry
area or use moisture absorber cartridges
Installation in level tubes
Place the cap lock in position and screw the two grub screws in to prevent it from
turning (anti-theft protection)
→
requires a slotted screwdriver, size 2 (not included in the scope of delivery)
Guide the sensor with the sensor cable into the level tube by hand. The sensor
cable must be free and extended as it hangs in the level tube; it must not change
its position as this would falsify the measurement results.
→
For system lengths of more than 50 m, cable strain relief is recommended,
e.g. using a straining clamp (see Accessories)
Screw the matching adapter ring onto the read-out unit. After installation, the
adapter ring will lie on the edge of the level cap lock. Secure the logger unit in the
adapter ring using the circlip supplied with the product.
→
requires circlip pliers (not included in the scope of delivery)
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The DCX logger can be connected locally to a laptop via the interface converter
cable.
The Logger 5 software can now be used to congure the device or to transmit the
measurement data stored in the DCX to the laptop.
→
Seal the read-out plug with the protective cap
Water level conguration
The surface of the interface plug integrated into the DCX represents the sys-
tem’s reference level. The measuring system is calibrated during installa-
tion. For this purpose, the run-off distance is measured (reference level-
surface of water, e.g. using a light plummet) and is entered in the water level
conguration in the Logger 5 software together with the density of the medium.
The system length is the sum of the hydrostatic water pressure measured at the
level sensor and the distance from the reference level that is entered.
After completing work on the measuring point, close the level tube seal by screw-
ing in the hexagon socket.
→
Allen wrench, size 5 (not included in the scope of delivery)
Tip:
To give the measuring point better protection against access, the Allen screw head
can be replaced by a screw head that is not available through usual commercial
outlets.
System length
Air Gap
Level
Water
surface
Sensor
reference line
Reference level
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Installation of relative data logger (VG versions)
Ambient pressure is compensated physically on VG versions. The ambient pres-
sure is fed to the back of the pressure sensor on the level sensor, via a capillary
tube integrated into the sensor cable.
If pressure compensation via the capillary tube is impeded or prevented by con-
tamination or moisture inside the capillary tube, the result of the level measure-
ment will be affected.
Standard version
The pressure compensation aperture is located be-
hind the removable protective tube, which is perforated.
This opening for the cable capillary is protected against water
penetration by a Goretex
®
diaphragm.
A thread to insert moisture absorber cartridges is provided on
the plug component of VG versions (minimum inner diameter
of tube: Ø 35 mm). It is advisable to use moisture absorber
cartridges for measuring points with harsh ambient conditions.
→
section: Maintenance / Moisture absorber cartridge
Version with moisture
absorber cartridge
(DCX-38 VG)
Moisture absorber cartridge
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Conguring and reading the data logger
The DCX is congured and read locally. The DCX is tted in the measuring point and is
connected to a laptop via the interface converter cable.
• The Logger 5 Software Manual is available at www.keller-druck.com
Installing the software
Only connect the DCX and the converter cable to your computer after the software has
been installed
• Install the KELLER “Driver K-104 K-114� software
• Install the KELLER “InstallerLogger5� software
→
The connection must not be broken during communication with the DCX (congura-
tion, data read-out). Always close the software program rst, and only then unplug
the DCX connection.
DCX time
The internal time for the DCX
is set by synchronization with
your computer’s (PC) time. To do this, enable the “Synchronize device time with PC
time“ eld in the Logger 5 software and then register the conguration on the DCX. The
DCX’s internal clock does not take account of summer time/winter time changeovers.
UTC (Universal Time Coordinated)
It is advisable to set the computer’s time zone to UTC.
Since UTC does not implement time corrections, the DCX’s measuring times remain
unchanged throughout the year and they can be converted to local time if necessary.
Time zones
If your computer’s time is assigned to a time zone (e.g. UTC +2), the PC clock will
change over automatically between summer and winter time.
Time corrections / changeovers of the DCX’s internal clock only take place if it is
synchronized with the computer (“Write conguration�).
Tip:
Congurations are only sent to the logger when you press the “Write conguration�
button. You can read the device conguration into the Logger 5 software again to check
the DCX settings.
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Verifying measured data
Ongoing measurements can be read out
with no need to interrupt the measurement
sequence.
As you read ongoing measurements, you
can set a ag (the measurement in progress
will be terminated and a new measurement
will be started immediately) or you can con-
tinue the ongoing measurement.
Continue measurement: disable the “Synchro-
nize device time with PC clock
�
eld and select
“Do not set ag
�
.
Tip: Verify online measured values directly, e.g. using a light plummet.
Device memory
Storage space management in the DCX is
handled automatically, and the memory can-
not be managed or deleted by the user.
Continuous (circular buffer)
The “Continuous� function (circular buffer) releases the data logger’s entire storage
space for the measurement in progress. As soon as the DCX’s storage capacity is
reached, the oldest saved measurement values (for the measurement in progress) are
overwritten by the latest measured values, until recording is stopped by the user.
Linear
The “Linear� function releases the data logger’s entire storage space for the measure-
ment in progress and terminates recording automatically as soon as the entire memory
has been lled with entries.
Data read in
Measured data that are read via the Logger 5 computer software are stored automa-
tically on the computer in a directory that can be freely chosen.
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Battery DCX-16
Lithium battery (type AAA)
KELLER product no. 557005.0017
Battery Series DCX
Lithium battery (type AA)
KELLER product no. 557005.0006
Maintenance
Dry the DCX thoroughly before opening it and make sure that the surrounding area
is dry while handling the device. Check all the sealing rings for signs of wear, dirt and
damage before using the logger unit again.
Battery
The battery status is not measured; instead, it is calculated using the averaged power
consumption. If the battery is changed or in case of a “Power on� reset, the display is
reset to 100%. This also happens if the same battery is inserted again, or if a dis-
charged battery is inserted.
To ensure that the logger operates reliably, it is advisable to replace the battery as soon
as its capacity falls below 30%, or after 5 years of operation.
Changing the battery, Series DCX
→
DCX-18: power is supplied by a rechargeable battery (cannot be exchanged)
Type designation Supply Battery type KELLER product no.
DCX-16 Battery Lithium battery (type AAA) 557005.0017
DCX-22 Battery Lithium battery (type AA) 557005.0006
DCX-25 PVDF Battery Lithium battery (type AA) 557005.0006
DCX-38 VG Battery Lithium battery (type AA) 557005.0006
Batteries must never be disposed of in normal household waste. To prevent possible
damage to the environment or to health due to uncontrolled waste disposal, this product
must be separated from other waste and recycled correctly in order to ensure sustain-
able use of the raw materials.
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To replace the battery, rst unscrew the knurled nut and then pull off the battery sleeve.
Carefully disconnect the battery from the plug and replace it.
After changing the battery, guide the plug into the opening in the sleeve, push the bat-
tery in and x it in the clip. Check the sealing rings. Re-t the battery sleeve, knurled
nut and xture.
Check the conguration (time, measurement interval, etc.) of the DCX via the Logger 5
software before using the product.
Watertightness
Products in the Series DCX logger are dustproof and are protected against the effects
of immersion in water (according to the pressure range).
The products are also protected against water splashes in the area of the read-out com-
ponent.
Exceptions: AA products: may be ooded for brief periods
DCX-22: continuous/long-lasting immersion
→
Please consult the datasheet for the precise specications.
Check that all sealing rings are clean and undamaged, and that the battery compart-
ment cover is rmly closed so that the Series DCX device is watertight.
Rechargeable battery
Type DCX-18 is powered by a rechargeable battery which can only be charged using
interface cable K-114M. The rechargeable battery is welded into the device and cannot
be exchanged. The status of the rechargeable battery is determined by measuring its
voltage. Avoid letting it discharge to a value of less than 10%. If the DCX is not being
used, recording should be stopped and the rechargeable battery should be recharged
once per year to prevent total discharge.
Type of
charging
Supply System length Charging current
(rechargeable
battery)
Charge time (full charging)
normal USB max. 20 m 90 mA ~ 8.5 h
fast Power unit max. 100 m 790 mA ~ 1 h
Vor öffnen Datenlogger trocknen! Keep dry before opening!
Battery plug Sealing rings
Battery sleeve Knurled nut
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Ventilation diaphragm (for VG versions only)
The diaphragm used for ventilation generally requires no maintenance.
The ventilation function of the diaphragm is impaired by matter adhering to or contami-
nating the ventilation aperture, or by contact between the diaphragm and solvents, to
such an extent that it may be necessary to replace the diaphragm. Test measurements
are carried out to verify the pressure compensation function.
Tip:
If blowing into the ventilation element during online measurements causes the value to
change visibly, the ventilation diaphragm is in proper working order.
Moisture absorber cartridges (optional)
The condition of the moisture absorber cartridge can be determined from the coloration
of the granulate. Blue = granulate is dry, pink = granulate is moist.
The granulate can be regenerated for re-use. To do this, pour the granulate from the
cartridge into a suitable container and dry it for 1 hour at 210 °C. The granulate releases
moisture into the surrounding environment and takes on a blue color again. After drying,
the granulate should be poured back into the absorber cartridge while it is still warm.
Note: The color of the granulate is less marked after regeneration than before because
the indicator inside the granulate particles migrates.
Input
ambient pressure
Moist granulate = pink Dry granulate = blue
Ventilation-DCX
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If the data logger is used in severely contaminated media, the pressure sensor
must be checked for contamination from time to time, and must be cleaned as
necessary. Never use sharp-edged tools such as screwdrivers, and never apply
pressure at any point on the diaphragm.
Cleaning the level sensor
The protective cap over the pressure sensor on the level sensor can be removed
by hand. Then rinse the sensor in owing lukewarm water.
The pressure sensor diaphragm is very sensitive.
Do not touch the diaphragm!
Cleaning the air pressure sensor (-AA versions)
To clean the pressure sensor as thoroughly as possible, remove the knurled nut,
battery sleeve and the protective sleeve of the sensor, and then re-install the bat-
tery sleeve, the protective cap for the interface plug and the knurled nut (without
the protective sleeve for the sensor) so that the electronics are protected against
water and moisture.
Rinse the sensor with clean lukewarm water. After cleaning and before tting the
sleeves, make sure that all parts are dry.
The pressure sensor diaphragm is very sensitive.
Do not touch the diaphragm!
Cleaning
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Setting the zero point
The pressure sensors built into the logger unit can be calibrated by the user. It may
be necessary to recalibrate the pressure sensors, for example after maintenance
work, if the measurement set-up is changed, or after the measuring station has
been operated for a year or more.
Calibration is carried out with the Logger 5 software.
Recommended interval between calibrations: 1–2 years.
When carrying out a calibration, note that the sensors must be checked/calibrated
in the same positions as they occupy in the measuring point (usually upright) and
they must be positioned next to each other at the same level.
Testing by the manufacturer
The DCX may also be sent to KELLER AG für Druckmesstechnik in order to
verify its measurement accuracy or for calibration. The following test options may
be chosen: simple check on the DCX without documentation, internal check with
documentation (5- or 11-point test protocol) or an internal check followed by ex-
ternal certication (DKD [German Calibration Service] or SCS [Swiss Calibration
Service] calibration certicate).
(Charges are payable for checks/verications, calibrations, protocols and certi-
cates)
Calibration
Series DCX devices measure and store the hydrostatic pressure of a uid in bar.
The density of the medium has a decisive inuence on the conversion of the pres-
sure [bar] to the water column level [mWS]. The height of the water column is
calculated with the following formula in the Logger 5 software:
P = hydrostatic pressure (0,1 bar = 10’000 N/m
2
)
ρ = water density (kg/m
3
) = 998,207 kg/m
3
@ 20°C
g = gravitational acceleration (= 9,80665 m/s
2
)
h = height of water column (m)
Level measurement with pressure sensors
Data logger
Plug for converter
cable
h = p =10000 N/m
2
=1,021 mWS
ρ
*
g 998,207 kg/m
3
*
9,80 m/s
2
This manual suits for next models
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Table of contents
