Primary standard for the calibration of dierential pressure
measuring instruments under static pressure
■
Reference instrument for factory and calibration laboratories for the testing, adjustment and calibration of pressure
measuring instruments
■
Complete, stand-alone system, also suitable for on-site use
Calibration technology
WIKA data sheet CT 31.56
Special features
■
Measuring ranges (= static pressure + dierential
pressure) up to 400 bar (5,000 psi) pneumatic,
up to 1,600 bar (23,200 psi) hydraulic
■
Total measurement uncertainty to 0.008 % of dierential
pressure plus 0.0001 % (1 ppm) of static pressure
■
Factory calibration included as standard, traceable to
national standards; with DKD/DAkkS calibration possible
as an option
■
High long-term stability with recommended recalibration
interval every ve years
■
Masses manufactured from stainless steel and aluminium,
can be adjusted to local gravity
Description
Proven primary standard
Pressure balances (dead-weight testers) are the most
accurate instruments available on the market for the
calibration of electronic or mechanical pressure measuring
instruments. The direct measurement of the pressure
(p = F/A), as well as the use of high-quality materials enable
a very small measurement uncertainty, in conjunction with an
excellent long-term stability.
The pressure balance (dead-weight tester) has therefore
been used for years in factory and calibration laboratories in
industry, national institutes and research laboratories.
Stand-alone operation
Due to its integrated pressure generation and the pure
mechanical measuring principle, the model CPB5600DP is
ideal for on-site use for maintenance and service.
Pressure balance for dierential pressure,
model CPB5600DP
Basic principle
Pressure is dened as the quotient of force and area. The
core component of the CPB5600DP is therefore a very
precisely manufactured piston-cylinder system, onto which a
mass load is applied in order to generate the individual test
points.
The mass load is proportional to the target pressure and this
is achieved through optimally graduated masses. As standard, these masses are manufactured to the standard gravity
(9.80665 m/s²), though they can be adjusted to a specic
location and also DKD/DAkkS calibrated.
WIKA data sheet CT 31.56
Data sheets showing similar products and accessories:
Dead-weight tester in compact design; model CPB3800; see data sheet CT 31.06
Pneumatic pressure balance; model CPB5000; see data sheet CT 31.01
Hydraulic pressure balance; model CPB5800; see data sheet CT 31.11
Pressure balance for high pressure; model CPB5000HP; see data sheet CT 31.51
CalibratorUnit; model CPU6000; see data sheet CT 35.02
∙ 03/2016
Page 1 of 14
Page 2
Easy operation
The pressure setting depends on the instrument design
and is either done via an integrated pump or from external
pressure supply via a metering valve. For ne adjustment,
a very precisely controllable spindle pump is tted, with a
precision spindle running within it.
The piston-cylinder system
As soon as the measuring system reaches equilibrium, there
is a balance of forces between the pressure and the masses.
The excellent quality of the system ensures that this pressure
remains stable over several minutes, so that the pressure
value for comparative measurements can be read without
any problems, or also so that more complex adjustments can
be carried out on the test item.
Both the piston and cylinder are manufactured from tungsten
carbide. This pairing of materials, in comparison to other
materials, has very low pressure and temperature coecients of expansion, which results in a very good linearity for
the eective area of the piston and a very high accuracy.
Piston and cylinder are very well protected against contact,
impacts or contamination from outside in a solid stainless-steel case. At the same time, overpressure protection is
integrated, which prevents the piston from being forced out
vertically and avoids damage to the piston-cylinder system in
the event of masses removal under pressure.
The masses are stacked on a mass carrier, which sits on the
piston shaft. The construction of the mass carrier provides
a very low centre of gravity for the stacked masses, which
minimises both the side thrust on the piston-cylinder system
and the friction. For relatively low starting pressures, a lighter
aluminium plate can be used instead of the mass carrier.
The overall design of the piston-cylinder system and the very
precise manufacturing of both the piston and the cylinder,
ensures excellent operating characteristics with long free-rotation time and low sink rates. Thus a high long-term stability
is ensured. Therefore, the recommended recalibration inter-
val is two or ve years depending on the conditions of use.
High-performance instrument range
The CPB5600DP instrument bases are available in the
following four designs:
■
Pneumatic base
- up to max. 100 bar (1,500 psi)
- with integrated pressure generation through priming
pump and spindle pump
- connection for external pressure supply
■
Pneumatic base with integrated gas to oil separator
- up to max. 400 bar (5,000 psi)
- connection for external pressure supply
- for use with hydraulic piston-cylinder systems with
M30 x 2 connection
- test items can be easily, dryly and cleanly calibrated with
air
■
Hydraulic base
- up to max. 1,000 bar (14,500 psi)
- with integrated pressure generation through priming
pump and spindle pump
- special designs available to 1,200 bar (17,400 psi)
■
Hydraulic high-pressure base
- up to max. 1,600 bar (23,200 psi)
- with integrated pressure generation through priming
pump and spindle pump
- for use with hydraulic high-pressure piston-cylinder
systems with M30 x 2 connection with sealing cone
The instruments include the components of two pressure
Force F
balances in one case. For the calibration of dierential
pressure gauges under a static pressure, the two systems
are separated by a by-pass valve.
One of the systems is used to generate the static pressure
with the second system generating the dierential pressure
(incl. static pressure). It is recommended that one of the sets
of ne increment masses is used for this (see accessories).
The instrument bases, pneumatic to 100 bar (1.450 psi) and
hydraulic, are tted with the patented ConTect quick-release
mechanism. This enables a quick and safe replacement of
the piston-cylinder system without any tools. The pneumatic
Eective area A
instrument version with separator is tted with a connection
for the piston-cylinder system with M30 x 2 female thread
and the hydraulic high-pressure base version is tted with a
M30 x 2 female thread with sealing cone.
Pressure p
The instrument bases are also available as individual
Piston-cylinder system
Page 2 of 14WIKA data sheet CT 31.56 ∙ 03/2016
instruments.
Page 3
Tables of masses
The following tables show the number of masses within a
mass set with their nominal mass values and the resulting
nominal pressures for the respective measuring ranges.
The masses are manufactured, as standard, to the standard
gravity (9.80665 m/s²) although they can be adjusted for any
local gravity.
Should the instrument not be operated under reference
conditions (ambient temperature 20 °C (68 °F), atmospheric
pressure 1,013 mbar (14.69 psi), relative humidity 40 %),
the relevant corrections must be made, for example with the
CPU6000 CalibratorUnit, see page 10.
Nominal eective area of the pistoncm²0.50.50.10.10.05
Versionhydraulichydraulic high pressure
Measuring range
1)
Required masseskg5032
Smallest stepbar
Sensitivity
4)
Nominal eective area of the pistoncm²0.050.02
Versionhydraulichydraulic high
Measuring range
1)
Required masseskg3434345033
Smallest steppsi
Sensitivity
4)
Nominal eective area of the pistoncm²0.50.10.050.050.02
Accuracies
Proportion of static pressure0.0001 % of reading
Proportion of dierential pressure
standard
Proportion of dierential pressure
premium
5) 6)
5) 6)
Lower limiting value of the measurement
uncertainty
1) Measuring range = static pressure + dierential pressure
2) Theroretical starting value; corresponds to the pressure value generated by the piston (by its own weight). To optimise the operating characteristics more masses should be loaded.
3) The smallest pressure change value that can be achieved based on the standard mass set. To reduce this, a set of ne increment masses is also available.
4) The sensitivity is the threshold of the measuring system. It is the pressure value of the smallest mass load, which brings the piston-cylinder system clearly and reproducibly out of
balance.
5) Measurement uncertainty assuming reference conditions (ambient temperature 20 °C (68 °F), atmospheric pressure 1,013 mbar (14.69 psi), relative humidity 40 %). For operation
without a CalibratorUnit, corrections must be made if required.
6) The accuracy of the dierential pressure is determined in accordance with the following calculation basis (see page 9).
depending on the measuring range; corresponds to the sensitivity of the piston
WIKA data sheet CT 31.56 ∙ 03/2016Page 5 of 14
Page 6
Piston-cylinder systems
Material
PistonTungsten carbide
hardened steel at hydraulic high pressure
CylinderTungsten carbide
Mass set1.4305 stainless steel and aluminium, non-magnetic
Weight
Piston-cylinder system, pneumatic or
hydraulic
Piston-cylinder system, hydraulic high
pressure
bar basic mass set, pneumatic
(incl. 2 carrying cases)
bar extension mass set, pneumatic
(incl. 2 carrying cases)
bar basic mass set, hydraulic
(incl. 2 carrying cases)
bar extension mass set, hydraulic
(incl. 2 carrying cases)
bar basic mass set, hydraulic high pressure
(incl. 2 carrying cases)
bar extension mass set, hydraulic high
pressure (incl. 2 carrying cases)
psi basic mass set, pneumatic
(incl. 2 carrying cases)
psi extension mass set 1, pneumatic
(incl. 2 carrying cases)
psi extension mass set 2, pneumatic
(only for 1,500 psi) (incl. 2 carrying cases)
psi basic mass set, hydraulic
(incl. 2 carrying cases)
psi extension mass set, hydraulic
(incl. 2 carrying cases)
psi basic mass set, hydraulic high pressure
(incl. 2 carrying cases)
psi extension mass set, hydraulic high
pressure (incl. 2 carrying cases)
Dimensions (W x D x H)
Carrying case for basic mass set400 x 310 x 310 mm (15.8 x 12.2 x 12.2 in)
Carrying case for extension mass set215 x 310 x 310 mm (8.5 x 12.2 x 12.2 in)
Storage case for the piston-cylinder system
(optional)
1.5 kg / 5.7 kg / (3.3 lbs / 12.6 lbs)
(incl. mass carrier and piston plate in optional storage case);
2 systems required
2.7 kg / 5.0 kg / (6.0 lbs / 11.0 lbs) (in optional storage case); 2 systems required
32.4 kg (71.4 lbs)
28.0 kg (61.7 lbs)
72.0 kg (158.8 lbs)
48.0 kg (105.8 lbs)
48.0 kg (105.8 lbs)
39.0 kg (86.0 lbs)
25.0 kg (55.1 lbs)
22.0 kg (48.5 lbs)
37.0 kg (81.6 lbs)
84.0 kg (185.2 lbs)
43.0 kg (94.8 lbs)
96.5 kg (212.8 lbs)
16.0 kg (35.3 lbs)
300 x 265 x 205 mm (11.8 x 10.4 x 8.1 in)
Base
Base version
Pneumaticup to max. 100 bar (1,500 psi); with priming pump, spindle pump and connection for external
supply
Pneumatic, with separatorup to max. 400 bar (5,000 psi);
for external supply with integrated gas to oil separator
for use with hydraulic pistons with M30 x 2 connection
Hydraulicup to max. 1,000 bar (14,500 psi); with internal pressure generation
up to max. 1,200 bar (17,400 psi) on request
Hydraulic, high pressureup to max. 1,600 bar (23,200 psi); with internal pressure generation
Page 6 of 14WIKA data sheet CT 31.56 ∙ 03/2016
Page 7
Base
Pressure transmission medium
PneumaticClean, dry, non-corrosive gases (e.g. air or nitrogen)
HydraulicOperating uid (1 litre is included in delivery), other media on request
Reservoir250 cm³
Connections
Connection for piston-cylinder
system
Test item connection2 pieces quick connector G ½ B female thread as standard, freely rotating, changeable; for further
External pressure connection6 mm SWAGELOK
Material
Piping in basepneumatic: 1.4571 stainless steel, 3 x 1 mm
Weight
Pneumatic base34.0 kg (75.0 lbs)
Pneumatic base with separator32.0 kg (70.6 lbs)
Hydraulic base38.5 kg (84.9 lbs)
Hydraulic high-pressure base37.0 kg (81.6 lbs)
Permissible ambient conditions
Operating temperature18 ... 28 °C (64 ... 82 °F)
Dimensions (W x D x H)
Base800 x 375 x 265 mm (31.5 x 14.8 x 10.4 in), for details, see technical drawings
ConTect quick connector on pneumatic and hydraulic base versions
M30 x 2 female thread on pneumatic base version with separator
M30 x 2 female thread with sealing cone on hydraulic high-pressure base version
threaded inserts, see accessories
®
threaded pipe connection; max. 110 % of the assigned measuring range;
only with pneumatic base version and pneumatic version with separator
Recommended recalibration interval2 to 5 years (dependent on conditions of use)
Approvals and certicates, see website
WIKA data sheet CT 31.56 ∙ 03/2016Page 7 of 14
Page 8
Transport dimensions for complete instrument
The complete instrument, in its standard version and standard scope of delivery, consists of 2 packaging units.
■
1 wooden box with instrument base, dimensions 980 x 580 x 560 mm (38.6 x 22.8 x 22.1 in)
■
1 pallet with piston and mass sets, dimensions 1,200 x 800 x 500 mm (47.3 x 31.5 x 19.7 in)
The overall weight is dependent on the instrument version and measuring range.
Weight
Wooden boxnetgross
Pneumatic base34.0 kg (75.0 lbs)43.5 kg (95.9 lbs)
Pneumatic base with separator32.0 kg (70.6 lbs)41.5 kg (91.5 lbs)
Hydraulic base38.5 kg (84.9 lbs)48.0 kg (105.8 lbs)
Hydraulic high-pressure base37.0 kg (81.6 lbs)46.5 kg (102.5 lbs)
PalletWeight
Version in barnetgross
Pneumatic
2 bar / 10 bar / 50 bar35.5 kg (78.3 lbs)50.5 kg (111.4 lbs)
100 bar63.5 kg (104.0 lbs)78.5 kg (173.1 lbs)
Hydraulic
60 bar / 250 bar / 600 bar75.0 kg (165.4 lbs)90.0 kg (198.5 lbs)
100 bar / 400 bar / 1,000 bar123.0 kg (271.2 lbs)138.0 kg (304.3 lbs)
1,600 bar92.5 kg (204.0 lbs)107.5 kg (237.0 lbs)
PalletWeight
Version in psinetgross
Pneumatic
30 psi / 150 psi / 1,000 psi50.0 kg (110.3 lbs)65.0 kg (143.3 lbs)
500 psi28.0 kg (61.7 lbs)43.0 kg (94.8 lbs)
1,500 psi87.0 kg (191.8 lbs)102.0 kg (224.9 lbs)
Hydraulic
1,000 psi / 5,000 psi / 10,000 psi87.0 kg (191.8 lbs)102.0 kg (224.9 lbs)
14,500 psi130.0 kg (286.7 lbs)145.0 kg (326.3 lbs)
23,200 psi118.0 kg (260.2 lbs)133.0 kg (293.3 lbs)
Page 8 of 14WIKA data sheet CT 31.56 ∙ 03/2016
Page 9
Calculation of the measurement uncertainty
The accuracy of the dierential pressure is the quadratic sum of the percentage of static pressure u
and the percentage of the dierential pressure value u
. (normally distributed). In this way, the minimum values of each of the
di
. (normally distributed)
stat
individual components are taken into account. What is calculated is the expanded measurement uncertainty U (k = 2), in which
the measurand lies with a probability of 95 %.
The measurement uncertainty is calculated as per the following equation:
U = k *
√
(u
stat
. / 2)² + (u
di.
/ 2)²
(k = 2 for 95 %)
Example 1:
Measuring range of the piston-cylinder system:10 bar
Accuracy of the piston-cylinder system:0.015 %
Static pressure:5 bar
Dierential pressure measured value:100 mbar
Measurement uncertaintyLower limiting value of the measurement
uncertainty
Proportion of static pressure0.0001 % of 5 bar = 0.005 mbar0.01 mbar
Proportion of dierential pressure0.015 % of 100 mbar = 0.015 mbar0.01 mbar
Overall accuracy
±2 *
√
(0.01 mbar/2)² + (0.015 mbar/2)² = 0.018 mbar which corresponds to ±0.018 % of reading
Example 2:
Measuring range of the piston-cylinder system:250 bar
Accuracy of the piston-cylinder system:0.008 %
Static pressure:200 bar
Dierential pressure measured value:2 bar
Measurement uncertaintyLower limiting value of the measurement
Proportion of static pressure
Proportion of dierential pressure
Overall accuracy
0.0001 % of 200 bar = 0.2 mbar0.2 mbar
0.008 % of 2 bar = 0.16 mbar0.2 mbar
±2 * √(0.2 mbar/2)² + (0.2 mbar/2)² = 0.283 mbar which corresponds to ±0.014 % of reading
uncertainty
WIKA data sheet CT 31.56 ∙ 03/2016Page 9 of 14
Page 10
Dimensions in mm (in)
The gure shows a pneumatic CPB5600DP base. The hydraulic version and hydraulic high-pressure version do not dier from
it dimensionally, only in the arrangement of the control elements.
Front view
Top view
Side view (left)
123456
7 8910 9117
1
Test item connector
Outlet valve
Test pressure gauge
2
(only to max. 1,000 bar (14,500 psi))
3
Inlet valve (only on pneumatic versions)
Threaded insert,
changeable
Quick-release
connector
with knurled
nut
Page 10 of 14WIKA data sheet CT 31.56 ∙ 03/2016
O-ring 8 x 2
4
Rotatable feet
5
Bypass valve
6
Spindle pump with star handle, removable
7
Connector for piston-cylinder system
8
Plug screw for oil reservoir (only on hydraulic versions)
9
Test item connection
10
Level
11
Priming pump
Page 11
CalibratorUnit model CPU6000
The models of the CPU6000 series are compact tools for use
with a pressure balance (dead-weight tester). In particular
when highly accurate measuring values, with measurement
uncertainties of less than 0.025 %, are required, complicated
mathematical calculations and corrections are necessary.
With the CPU6000 in combination with the CPB-CAL (iPad
app) and/or WIKA-CAL (PC software) all critical ambient
parameters can be registered and automatically corrected.
®
The CPU6000 series is made up of three
instruments
Weather station, model CPU6000-W
The CPU6000-W provides measured values such as
atmospheric pressure, relative humidity and the ambient
temperature of the laboratory environment.
Pressure balance sensor box, model CPU6000-S
The CPU6000-S measures the piston temperature and
displays the oating position of the masses.
Digital multimeter, model CPU6000-M
The CPU6000-M fulls the function of a digital multimeter
and power supply unit when electronic pressure transmitters
must be calibrated.
CPU6000 series and iPad® app CPB-CAL
Typical application
CPB-CAL iPad® app
The iPad
balances (dead-weight testers) or the reference pressure
while taking the measured parameters from the CPU6000
into account. The conversion can be carried out in all
common pressure units. As an additional parameter, the local
gravity can be given for location-independent measurements.
WIKA-CAL PC software - Weight calculator
With the demo version of the WIKA-CAL software and a CPB
series pressure balance (dead-weight tester), the masses to
be applied and the corresponding reference pressure can be
determined. The pressure balance data (dead-weight tester
data) can be entered into the database manually or imported
automatically via an XML le available online.
All ambient parameters and piston temperature can be
entered manually into WIKA-CAL or can be measured
automatically with the CPU6000 series, so that the highest
accuracy can be achieved. WIKA-CAL demo version can be
downloaded free of charge from the WIKA website.
Further specications on the CPU6000 series can be found
in data sheet CT 35.02.
For details of the WIKA-CAL calibration software see data
sheet CT 95.10.
®
application calculates the masses for pressure
Model CPU6000-W, CPU6000-S, CPB5800 and PC with
WIKA-CAL software
WIKA-CAL PC software - Weight calculator
WIKA data sheet CT 31.56 ∙ 03/2016Page 11 of 14
Page 12
Further pressure balances / dead-weight testers within our calibration technology
programme
Dead-weight tester in compact design, model CPB3800
Measuring ranges:
Hydraulic1 ... 120 to 10 ... 1,200 bar
(10 ... 1,600 to 100 ... 16,000 psi)
Accuracy:0.05 % of reading
0.025 % of reading (optional)
For specications see data sheet CT 31.06
Pneumatic pressure balance, model CPB5000
Measuring ranges:
Pneumatic-0.03 ... -1 to +0.4 ... +100 bar
(-0.435 … -14 to +5.8 … +1,500 psi)
Accuracy:0.015 % of reading
0.008 % of reading (optional)
Dead-weight tester in compact design,
model CPB3800
For specications see data sheet CT 31.01
Hydraulic pressure balance, model CPB5800
Measuring ranges:
HydraulicSingle-piston measuring ranges:
1 ... 120 to 2 ... 300 bar
(10 ... 1,600 to 30 ... 4,000 psi)
Dual-piston measuring ranges:
1 ... 60 bar / 10 ... 700 bar to 1 ... 60 bar /
20 ... 1,400 bar
(10 ... 800 psi / 100 ... 10,000 psi to
10 ... 800 psi / 200 ... 20,000 psi)
Accuracy:0.015 % of reading
up to 0.006 % of reading (optional)
For specications see data sheet CT 31.11
Pressure balance for high pressure, model CPB5000HP
Pneumatic pressure balance, model CPB5000
Hydraulic pressure balance, model CPB5800
Measuring ranges:
Hydraulic25 ... 2,500, 25 ... 4,000 or 25 ... 5,000 bar
Pressure balance for high pressure,
model CPB5000HP
Page 13
Accessories
Set of ne increment masses M1 and F1
The masses included in the standard scope of delivery are
ideally suited for everyday use. If even smaller intermediate
values need to be generated, using one of the class M1 or
F1 set of ne increment masses with the following masses is
recommended:
1 x 50 g, 2 x 20 g, 1 x 10 g, 1 x 5 g, 2 x 2 g, 1 x 1 g,
1 x 500 mg, 2 x 200 mg, 1 x 100 mg, 1 x 50 mg, 2 x 20 mg,
1 x 10 mg, 1 x 5 mg, 2 x 2 mg, 1 x 1 mg
Adapter sets for quick-release connector
As a standard, the pressure balance is equipped with a
quick-release connector for connecting the test item. For this
purpose, the following threaded inserts, which can be easily
changed, are available:
■
Adapter set: G ¼, G ⅜, ½ NPT, ¼ NPT and M20 x 1.5
■
Adapter set NPT: ⅛ NPT, ¼ NPT, ⅜ NPT and ½ NPT
Additionally, the adapter sets include spare O-rings as well
as a spanner with SW32 ats and SW14 ats, for changing
the adapters.
Other threaded inserts are available on request.
Set of ne increment masses
Adapter set
Designation/VersionOrder no.
Set of ne increment masses (1 mg up to 50 g), class F17093874
Set of ne increment masses (1 mg up to 50 g), class M114025325
Adapter set for quick-release connector in case with G ¼, G ⅜, ½ NPT, ¼ NPT and M20 x 1.5 threaded inserts for
insertion in the knurled nut on the test item connector
Adapter set “NPT” for quick-release connector in case with ⅛ NPT, ¼ NPT, ⅜ NPT and ½ NPT threaded inserts for
insertion in the knurled nut on the test item connector
90° angled connection piece, for test items with back mounting connection1564838
O-ring set consisting of 5 pcs. 8 x 2 and 5 pcs. 4 x 2.212328562
Operating uid for CPB5000 up to max. 4,000 bar (60,000 psi), 1 litre2099882
Cleaning set for ConTect systems, pneumatic12485943
Cleaning set for ConTect systems, hydraulic12481425
WIKA data sheet CT 31.56 ∙ 03/2016Page 13 of 14
2036941
12563626
Page 14
Scope of delivery
Options
■
Base
■
Priming pump
■
Spindle pump for lling, pressure generation and ne
pressure adjustment
■
Piston connection with ConTect quick-release connector
(on pneumatic and hydraulic base)
■
Piston connection with M30 x 2 female thread (on
pneumatic base with separator and hydraulic high
pressure)
■
2 quick connectors for test items
■
2 piston-cylinder systems with mass carrier
■
2 basic mass sets in carrying case
■
2 extension mass sets in carrying cases (depending on
the measuring range)
■
Masses, manufactured to local gravity (standard value:
9.80665 m/s²)
■
Operating uid 1.0 litre (only for hydraulic version) or
0.25 litre (for separator version)
■
Additional sealing set
■
Operating instructions in German and English language
■
Factory calibration certicate
■
Systems with increased accuracy to 0.008 % (depending
on measuring range)
■
Further pressure units
■
Storage case for piston-cylinder systems
■
DKD/DAkkS calibration certicate
Ordering information
Model / Instrument version / Measuring range / Accuracy / Gravity value g / Storage case for piston-cylinder systems / Installation of CPU6000-S CalibratorUnit sensor technology / Calibration for the pressure balance / Additional ordering information
The specications given in this document represent the state of engineering at the time of publishing.
We reserve the right to make modications to the specications and materials.