LR-Cal LDW-H deadweight tester / pressure balance
hydraulic, up to 1,400 bar
Accuracy up to ±0.006% of measured value

Hydraulic
Pressure ranges from 1...120 bar to 1...1,400 bar
and from 10...1,600 psi to 10...20,000 psi
Accuracy ±0.006% or ±0.015% of measured value
Single and double piston systems

Scheme: LR-Cal LDW-H single piston cylinder system

Scheme: LR-Cal LDW-H
single piston system for ranges 120 to 300 bar

Schema: LR-Cal LDW-H Doppel-Kolbenzylindersystem

Scheme: LR-Cal LDW-H
double piston system for higher pressure ranges

Description

LR-Cal LDW-H description

Proven primary standard
Pressure balances (deadweight tester) are the most accurate devices 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 allow a very small measurement uncertainty in combination with an excellent long-term stability of 5 years (recommendation according to the German Calibration Service (DAkkS). Pressure balances / deadweight tester have been used for years in factory and calibration laboratories of industry, national institutes and research institutes.

Autonomous mode of operation
Due to the integrated pressure generation as well as the purely mechanical measuring principle, the LR-Cal LDW-H deadweight tester is also ideally suited for on-site use, maintenance and service.

Basic principle
Pressure is defined as the quotient of force and area. Accordingly, the heart of the LR-Cal LDW-H pressure balance is a very precisely manufactured piston/cylinder system, which is loaded with mass supports to generate the individual test points.

The mass support is proportional to the target pressure and is achieved by optimally graduated disc weights. These disc weights are manufactured as standard to the standard acceleration of gravity of 9.80665 m/s², but can also be optionally adapted to their specific location of use and also DAkkS-calibrated.

Simple mode of operation
In the sturdy basic unit, even large test volumes can be easily filled and compressed with the integrated pre-pressure pump and 250 ml tank. For further pressure build-up, a very precisely adjustable spindle pump with internal rotating spindle is installed.

As soon as the measuring system is in a floating state, there is a balance of forces between the pressure and the mass supports. Due to the excellent workmanship of the system, this pressure remains stable for several minutes, so that the pressure values for comparative measurement or even more extensive adjustment work can be carried out on the test specimen without any problems.

Two basic unit versions
The LR-Cal LDW-H deadweight tester is available in two versions, both with integrated pressure supply:

Basic unit, hydraulic - "Standard
Type LR-Cal LDW-H-S
up to max. 1,200 bar (16,000 psi)
Pressure transmission media: mineral oil, optional: sebacate oil, brake fluid, Skydrol or Fomblin oil
Basic unit, hydraulic - "high pressure
Type LR-Cal LDW-H
up to max. 1,400 bar (20,000 psi)
Pressure transmission media: mineral oil, optional: sebacate oil

Standardmäßig sind beide Grundgeräte-Ausführungen mit einem Anschluss für das Kolbenzylindersystem mit Außengewinde G 3/4 ausgerüstet. Beim Grundgerät Ausführung "Standard" ist optional eine Schnellspannaufnahme für das Kolbenzylindersystem erhältlich. Diese ermöglicht einen schnellen und sicheren Wechsel des Kolbenzylindersystems ohne Werkzeug.

The test specimen is connected to a quick-connect system without tools. Due to the free-running knurled nut, the test specimens can be aligned as required. A threaded insert with a 1/2" BSP female thread is included as standard. Further threaded inserts are optionally available, with which all common pressure gauges can be connected.

Special features:

Total measurement uncertainty up to ±0.006% of measured value
With traceable factory calibration certificate as standard (option: DAkkS calibration certificate)
Very high long-term stability, recommended recalibration only every 5 years
Stainless steel mass disks, optional adaptation to local gravitational acceleration of the application site
Compact dimensions

Applications:

Primary standard for the measurand pressure, up to max. 1,400 bar (20,000 psi), hydraulic
Reference instrument for factory and calibration laboratories for testing, adjusting and calibrating pressure measuring instruments of all types
Self-sufficient complete system, also suitable for on-site use.

Piston cylinder system: explanations

LR-Cal LDW-H piston cylinder system

Piston cylinder systems for the LR-Cal LDW-H pressure balance are available - depending on the measuring range - in two fundamentally different versions:

Single piston system
Type LR-Cal LDW-H-EKZ
for pressure ranges 120 bar to 300 bar
Double piston system
Type LR-Cal LDW-H-DKZ
for all higher pressure ranges.

High accuracy over a wide measuring range
The LR-Cal LDW-H-DKZ double piston-cylinder systems have two measuring ranges in one housing with automatic measuring range switching from the low-pressure to the high-pressure piston. This provides the user with an extremely flexible measuring device that can cover a wide measuring range with high accuracy using only one piston-cylinder unit and one mass set. Furthermore, two test points can be approached by the operator with only one mass support.

The pistons and cylinders are made of hardened steel and tungsten carbide, respectively. These material pairings have low coefficients of pressure and temperature expansion, which result in very good linearity of the effective piston cross-sectional area and high accuracy.

Piston and cylinder are very well protected against contact, shock or contamination from the outside in a solid housing made of stainless steel or hardened tool steel. At the same time, an overpressure safety device is integrated, which prevents the piston from being pushed out vertically and thus prevents damage to the piston-cylinder system in the event that disk weights are removed under pressure.

The disk weights are stacked directly onto the piston skirt. This makes it easier for the operator to place the disc weights and also enables a low starting value.

The overall design of the piston-cylinder unit and the precise manufacture of the piston and cylinder ensure extremely low frictional forces, which result in excellent running properties with a high free rotation time and low sink rates. This ensures very high long-term stability. The recommended recalibration cycle is therefore five years depending on the conditions of use.

LR-Cal LDW-H-EKZ

Single piston system
for pressure ranges 120 to 300 bar

LR-Cal LDW-H-DKZ

Double piston system
for higher pressure ranges

Piston cylinder systems: pressure ranges + specification

LR-Cal LDW-H piston cylinder systems: pressure ranges + specification

Single piston pressure ranges:

Measuring Range 1)	bar, kg/cm²	1...120	2...300
Required masses	kg	49.7	49.6
Smallest step 2) standard set of masses	bar, kg/cm²	0.5	2.5
Smallest step 3) optional fine increment weights	bar, kg/cm²	0.02	0.05
Nominal cross-sectional area of the piston	cm²	0.4032	0.1613
Measuring Range 1)	psi, lb/in²	10...1,600	30...4,000
Required masses	kg	45.5	45.3
Smallest step 2) standard set of masses	psi, lb/in²	5	20
Smallest step 3) optional fine increment weights	psi, lb/in²	0.2	0.5
Nominal cross-sectional area of the piston	cm²	0.4032	0.1613
Measuring Range 1)	kPa	100...12,000	200...30,000
Required masses	kg	49.7	49.6
Smallest step 2) standard set of masses	kPa	50	250
Smallest step 3) optional fine increment weights	kPa	2	5
Nominal cross-sectional area of the piston	cm²	0.4032	0.1613
Accuracy
Standard 4) 5)	% of measured value	0.015	0.015
Optional 4) 5)	% of measured value	0.007	0.006
Pressure transmission medium
Standard	Hydraulic fluid based on mineral oil
Optional	Sebacate oil Brake fluid Skydrol Fomblin oil
Material
Piston		Steel	Steel
Cylinder		Bronze	Steel
Set of masses	Stainless steel, non-magnetic
Weights
Piston-cylinder system	kg	1	0.8
Storage case for piston-cylinder system	kg	3.1	3.1
"bar" standard mass sets (in 2 cases)	kg	61.3	61.2
"psi" standard mass sets (in 2 cases)	kg	57.1	56.9
Optional "bar" fine increment masses	kg	0.33	0.5
Optional "psi" fine increment masses	kg	0.23	0.34
Dimensions
Carrying case for standard mass sets	mm	W 400 x D 310 x H 310
Optional storage case for piston-cylinder systems	mm	W 300 x D 265 x H 205

Double piston pressure ranges:

Measuring Range 1)	bar, kg/cm²	1...60 / 10...700	1...60 / 20...1.200	1...60 / 20...1.400
Required masses	kg	57.4	49.2	57.4
Smallest step 2) standard set of masses	bar, kg/cm²	0.5 / 5.0	0.5 / 10	0.5 / 10
Smallest step 3) optional fine increment masses	bar, kg/cm²	0.01 / 0.1	0.01 / 0.2	0.01 / 0.2
Nominal cross-sectional area of the piston	cm²	0.8065 / 0.0807	0.8065 / 0.0403	0.8065 / 0.0403
Measuring Range 1)	psi, lb/in²	10...800 / 100...10,000	10...800 / 200...16,000	10...800 / 200...20,000
Required masses	kg	56.4	45	56.4
Smallest step 2) standard set of masses	psi, lb/in²	5 / 50	5 / 100	5 / 100
Smallest step 3) optional fine increment masses	psi, lb/in²	0.1 / 1	0.1 / 2	0.1 / 2
Nominal cross-sectional area of the piston	cm²	0.8065 / 0.0807	0.8065 / 0.0403	9.8065 / 0.0403
Measuring Range 1)	kPa	100...6,000 / 1,000...70,000	100...6,000 / 2,000...120,000	100...6,000 / 2,000...140,000
Required masses	kg	57.4	49.2	57.4
Smallest step 2) standard set of masses	kPa	50 / 500	50 / 1,000	50 / 1,000
Smallest step 3) optional fine increment masses	kPa	1 / 10	1 / 20	1 / 20
Nominal cross-sectional area of the piston	cm²	0.8065 / 0.0807	0.8065 / 0.0403	0.8065 / 0.0403
Accuracy
Standard 4) 5)	% of measured value	0.015	0.015	0.025
Optional 4) 5)	% of measured value	0.006	0.007	0.007
Pressure transmission medium
Standard	Hydraulic fluid based on mineral oil
Optional		Sebacate oil Brake fluid Skydrol Fomblin oil	Sebacate oil Brake fluid Skydrol Fomblin oil	Sebacate oil
Material
Piston		Tungsten carbide / steel	Tungsten carbide /steel	Tungsten carbide / steel
Cylinder		Steel / Tungsten carbide	Steel / Tungsten carbide	Steel / tungsten carbide
Set of masses	Stainless steel, non-magnetic
Weight
Piston-cylinder system	kg	2	2	2
Storage case for piston-cylinder system (optional)	kg	3,1	3,1	3,1
"bar" standard set of masses (in 2 wooden cases)	kg	69	60,8	69
"psi" standard set of masses (in 2 wooden cases)	kg	68	56,6	68
Optional "bar" fine increment masses	kg	0,5	0,5	0,5
Optional "psi" fine increment masses	kg	0,34	0,34	0,34
Dimensions
Carrying case for standard mass sets	mm	B400 x T310 x H310
Optional storage case for piston-cylinder systems	mm	B300 x T265 x H205

1) Theoretical starting value; corresponds to the pressure value generated by the piston or the piston and its make-up weights (bei their own weight). To optimise the operating characteristics more weights should be loaded.

2) The smallest pressure change value that can be achieved based on the standard weight set. To reduce this, a set of trim masses is also available. See Accessories.

3) The smallest pressure change value that can be achieved based on the optional fine increment weights. For further reductions, an accessory of class M1 or F1 trimm masses is available.

4) The accuracy from 10% of the measuring range is based on the measured value. In the lower range, the accuracy is 0.03% of reading for single-range piston-cylinder-systems and 0.025% of reading for dual-range piston-cylinder-systems.

5) Measuring uncertainty assuming reference conditions (ambient temperature 20°C, air pressure 1,013 mbar, relative humidity 40%).Corrections mus be made if required.

Base unit: specification

LR-Cal LDW-H base unit: specification

Base version
Hydraulic, standard, LR-Cal LDW-H-S		up to a max. 1,200 bar / 16,000 psi; with internal pressure generation
Hydraulic, high-pressure, LR-Cal LDW-H-H		up to a max. 1,400 bar / 20,000 psi; with internal pressure generation
Pressure transmission medium
Standard		Hydraulic fluid based on mineral oil
Optional		Sebacate oil, Brake fluid, Skydrol or Fomblin oil (dependant upon measuring range)
Fluid reservoir	cm³	250
Connections
Connection for piston-cylinder system		3/4" BSP male; optional: quick-release connector (not for 1,400 bar version)
Test item connector		1/2" BSP female quick connector as standard, freely rotating, changeable (for other threaded inserts, see accessories)
Material
Piping in instrument base		Stainless steel 1.4404, 6 x 2 mm
Weight
Base"standard", LR-Cal LDW-H-S	kg	18.0 (19.0 with optional quick-release connector)
Base "high-pressure", LR-Cal LDW-H-H	kg	18.0
Optional storage case for basement	kg	8.5
Permissible ambient conditions
Operating temperature	°C	18...28
Dimensions
Base (both versions)	mm	W 400 x D 375 x H 265

LR-Cal LDW-H approvals + certificates

CE conformity: pressure equipment directive 97/23/EG (module A)
Certificate of calibration: factory certificate, traceable. Optional DAkkS certificate of calibration

Scope of standard supply

LR-Cal LDW-H scope of standard supply

Base unit LR-Cal LDW-H
Priming pump
Spindle pump (pressure generation and fine adjustment)
Piston connection with 3/4" BSP male thread
Quick-fit connector for unit under test, with thread insert 1/2" BSP female, changeable
Piston cylinder system
Standard set of masses in carrying case, calibrated to standard gravity 9.80665 m/s²
Bottle with 1 liter operating fluid (special mineral oil based hydraulic fluid)
Factory certificate of calibration (traceable)
Operating manual DE+EN

Options + accessories + spare parts

Product VIDEO

LR-Cal LDW-H options + accessories + spare parts

Accuracy ±0.006/0.007%
of measured value

Code:
...-G06 / ...-G07

Option:
Extended accuracy
±0.006% bzw. ±0.007% of measured value
(depending on pressure range)

Calibration to special
local gravity

Code:
DW-H-KZS-GRV + LDW-H-MS-GRV

Option:
Mass set manufactured to special local gravitational acceleration at the place of use of the device
(deviating from standard = 9.80665 m/s²)

Piston cylinder system
with quick-fit connector

Code:
LDW-H-S-CT + LDW-H-KZS-CT

Option:
Piston cylinder system with quick release connection instead of M30x2, this allows the piston-cylinder system to be changed without tools.

Only for basic unit up to max. 1,200 bar

DAkkS-
certificate

Code:
LDW-H-MPZERT-DKD

Option:
DAkkS calibration certificate
(instead of factory calibration certificate)

Version for
sebacate oil

Code::
...-SO

Option:
Version for operating medium
Sebacate oil
(instead of mineral oil)

for basic unit up to 1,200 bar
for basic unit up to 1,400 bar

Version for
brake fluid

Code:
...-BF

Option:
Version for operating medium
brake fluid
(instead of mineral oil)

for basic unit up to 1,200 bar

Version for
Skydrol

Code:
...-SD

Option:
Version for operating medium
Skydrol
(instead of mineral oil)

for basic unit up to 1,200 bar

Version for
Fomblin oil

Code:
...-FO

Option:
Version for operating medium
Fomblin oil
(instead of mineral oil)

for basic unit up to 1,200 bar

Pressure unit
kg/cm²

Code:
LDW-H-MS-KGC

Option:
Mass set manufactured on
pressure unit "kg/cm²"
(instead of "bar")

Pressure unit
kPa

Code:
LDW-H-MS-KPA

Option:
Mass set manufactured on
Pressure unit "kPa
(instead of "bar")

Pressure unit
MPa

Code:
LDW-H-MS-MPA

Option:
Mass set manufactured on
Pressure unit "MPa
(instead of "bar")

Pressure unit
psi

Code:
LDW-H-MS-PSI

Option:
Mass set manufactured on
pressure unit "psi
(instead of "bar")

Mass set extension
finer graduation

Code:
LDW-H-FMS-...

Option:
Additional finer set of weights to increase the "resolution".

In addition to the standard weight set

Motorized piston
drive

Code:
LDW-H-E-230

Option/Accessory:
Electric drive unit (230 VAC) for the piston-cylinder system

only for ranges
up to 700 bar and 1,200 bar

Case for
base unit

Code:
LDW-H-KOFFER-BM

Accessory:
Transport and storage case for the basic unit

Case for
piston cylinder system

Code:
LDW-H-KOFFER-KZS

Accessory:
Transport and storage case for the piston cylinder system

Inremental weight set
class F1

Artikel-Nr.:
LDW-FMS-F1

Accessory:
Fine incremental weight set class F1
1 mg bis 50 g

Inremental weight set
class M1

Code:
LDW-FMS-M1

Accessory:
Fine incremental weight set class M1
1 mg bis 50 g

Adapter set
BSP

Code:
LDW-ADAPTER-BSP

Spare part:
Set of BSP adapter for test item port

to 1/2" + 1/4" + 3/8" + 1/2" BSP

(1 x included in standard supply)

Adapter set
NPT

Code:
LDW-ADAPTER-NPT

Accessory:
Set of NPT adapter for test item port

to 1/8" + 1/4" + 3/8" + 1/2" NPT

Angle connector
90° angle

Code:
CPB5000-WA90

Accessory:
90° elbow connector
e.g. for connecting pressure gauges with rear pressure connection to the test connection of the device

Separator
max. 700 bar

Code-Nr.:
LDW-TV-M-0700

Accessory:
Separator max. 700 bar
with membrane
To separate the media of the test specimen and the device

Separator
max. 1,200 bar

Code:
LDW-TV-M-1200

Accessory:
Separator max. 1,200 bar
with membrane
To separate the media of the test specimen and the device

Seal set for piston
and pressure port

Code:
CPB5000-R-SET

Spare part:
Seal kit for piston mount and test piece connection

LR-Cal LDW-H product VIDEO

Basic information on pressure balances / deadweight tester see here...

LR-Cal LDW-H deadweight tester / pressure balancehydraulic, up to 1,400 barAccuracy up to ±0.006% of measured value

Description

LR-Cal LDW-H description

Piston cylinder system: explanations

LR-Cal LDW-H piston cylinder system

LR-Cal LDW-H-EKZ

LR-Cal LDW-H-DKZ

Piston cylinder systems: pressure ranges + specification

LR-Cal LDW-H piston cylinder systems: pressure ranges + specification

Single piston pressure ranges:

Double piston pressure ranges:

Base unit: specification

LR-Cal LDW-H base unit: specification

LR-Cal LDW-H approvals + certificates

Scope of standard supply

LR-Cal LDW-H scope of standard supply

Options + accessories + spare parts

Product VIDEO

LR-Cal LDW-H options + accessories + spare parts

Accuracy ±0.006/0.007%of measured value

Calibration to speciallocal gravity

Piston cylinder systemwith quick-fit connector

DAkkS-certificate

Version forsebacate oil

Version forbrake fluid

Version forSkydrol

Version forFomblin oil

Pressure unitkg/cm²

Pressure unitkPa

Pressure unitMPa

Pressure unitpsi

Mass set extensionfiner graduation

Motorized pistondrive

Case forbase unit

Case forpiston cylinder system

Inremental weight setclass F1

Inremental weight setclass M1

Adapter setBSP

Adapter setNPT

Angle connector90° angle

Separatormax. 700 bar

Separatormax. 1,200 bar

Seal set for pistonand pressure port