BALUN BL510 User manual

User Manual
Model BL510 Portable Deadweight Tester

Dear Customer,
We are delighted that you have decided to buy a BL510 portable deadweight tester. Please read
these operating instructions for the BL510 portable deadweight tester carefully before connecting
and configuring it, and operate the device in compliance with the instructions. Operational safety
and the function of the device can only be guaranteed if the generally applicable legal safety and
accident prevention regulations, plus the safety instructions provided in the operating instructions,
are complied with.
We do not accept liability for any damage caused by improper use or incorrect operation. Please
ensure that all persons operating the device have read and understood the operating instructions.
Keep these operating instructions in a safe place so that they are accessible at all times when
needed. If you require further information, please don’t hesitate to contact with us using the
following contact details:
1322, F/3, Bldg 1, 33 Zique Rd, Haidian, Beijing 100095, China
Phone: [phone] [email protected] www.baluntech.com

Table of Contents
1. INTRODUCTION .................................................................................................................................................1
2. SPECIFICATION .................................................................................................................................................5
3. SAFETY REQUIREMENTS ..................................................................................................................................8
4. SETTING UP THE DEADWEIGHT TESTER ................................................................................................... 10
5. OPERATING THE DEADWEIGHT TESTER ................................................................................................... 12
5.1 Preparation ................................................................................................................................................. 12
5.2 Pressure Transforming Media....................................................................................................................... 12
5.3 Operation ................................................................................................................................................... 12
6. MAINTENANCE ........................................................................................................................................... 14
6.1 Cleaning and service tips ............................................................................................................................. 14
6.3 Oil changes ................................................................................................................................................ 14
6.4 Maintenance schedule ................................................................................................................................. 15
7. TROUBLESHIOOTING ................................................................................................................................. 16

Page 1
1. INTRODUCTION
1.1 General Description
The model BL510 portable deadweight tester provide a precise means for generating pressure with high accuracy that
can be used as a primary calibration standard. The unit's built-in shuttle valve provides the means to control the rate of
pressure increase, while precision adjustment is accomplished with an integral micro vernier displacement valve. An ideal
product that offers a rugged field ready primary standard, certified to yield consistent accurate results.
1.2 Application
 Primary Pressure Standard in lab or site
 Secondary Reference Pressure Standard in lab or site
1.3 Operating Principle
A deadweight tester is based on a high accurate manufactured piston and cylinder assembly. This cylinder is mounted in
a column. The piston can rotate and freely move up and down. Accurately calibrated masses are loaded on top of the
vertically mounted piston. A pressure is applied on the bottom of the piston to lift the piston with masses. This creates a
balance between the downward force made by the masses and the upward force made by the pressure. With the known
effective area of the piston the pressure can be calculated.

Page 2
In formula:
P=F/A
Where:
 P = the pressure being derived
 F = the force applied by the weights
 A = the effective area of the piston cylinder
1.4 Determine of the pressure
The reference level of the deadweight tester is at the top of the sealing of the pressure connection. If the weight set is
marked with a pressure unit (MPa; bar; psi or kg/cm²) the pressure can be determined by the formula:
P= m·g(1
－ ρa ／ ρm) .
So (1 ＋ λPo)[1 ＋ (αp ＋ αc)(t － 20)]
Where is:
 P: Measurement pressure Pa (MPa)
 m: Mass (kg)
 g: Standard gravity 9.80665 m/s² or customized local gravity
 ρa: The density of the ambient air at the reference level of the deadweight tester, the typical value is 1.2 kg/m³

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 ρm: Mass density, ρ value of stainless steel =7.93x10³kg/m3 , ρ value of carbon steel =7.8x103kg/m3, ρ value of
Aluminum =2.7 x10³kg/m3
 So: effective area at zero pressure (m²) @ t=20℃
 Po: This is pressure value when piston module doesn’t be deformed, can be instead by P, (MPa)
 αp: thermal expansion coefficient piston, the typical value is 4.5×10-6 ℃-1
 αc: thermal expansion coefficient cylinder, the typical value is 4.5×10-6 ℃-1
 T: The temperature of piston (℃)
 λ: pressure distortion coefficient piston + cylinder (MPa-¹), Example: the piston and cylinder is tungsten carbide
material, cylinder outside diameter is 22 mm, cylinder height is 30 mm, piston length is 38 mm, the λ value as
below:
Part Number
Pr
essure Range
Piston Diameter
Piston Area
λ value of tungsten carbide
KY0.6
(0.04~0.6)MPa
11.28 mm
1 cm
2
N
egligible
KY1
(0.04~1)MPa
11.28 mm
1 cm
2
N
egligible
KY6
(0.1~6)MPa
5.046 mm
0.2 cm
2
N
egligible
KY25
(0.5~25)MPa
3.568 mm 0.1 cm2 7.413 ×10-7 MPa
-
¹
KY60
(1~60)MPa
2.523 mm 0.05 cm2 7.413 ×10-7 MPa
-
¹
KY70
(1~70)MPa
2.523 mm 0.05 cm2 7.196 ×10-7 MPa
-
¹
KY100
(1~100)MPa
2.523 mm 0.05 cm2 7.196 ×10-7 MPa
-
¹
1.5 Piston cylinder assembly

Page 4
The piston cylinder assembly is the heart of the dead weight tester and responsible for its high accuracy. We
manufactures piston cylinder with accuracies from 0.05% up to 0.005% of reading. To give an idea of the manufacturing
skills, the space between the piston and the cylinder is in the um range and can only be measured in a climate room. To
guarantee an excellent metrology-logic characteristics, all pistons and cylinders are made of tungsten carbide. Because of
the extreme hardness of this material, the pressure distortion (expansion) coefficient is negligible. The low friction
coefficient provides minutes of turning with just a little swing of the masses.
1.6 Effective Area
For all dead weight testers, the effective area is determined by cross
floating with a known reference primary standard deadweight tester. The
exact pressure can be calculated. As per the formula of the item 1.4,
compensation factors are listed for air buoyancy, local gravity, surface
tension of the used oil and temperature and pressure expansion of the
piston cylinder assembly. All necessary data are listed in the calibration
certificate provided with each dead weight testers.
1.7 Mass Set
The masses of the dead weight tester are made of carbon steel or nonmagnetic stainless steel. They are laser marked
with a serial number and mass or the equivalent pressure. The weights are tare out to add stainless steel to an internal
chamber. This is easy for recalibration or adjustments for gravity compensation. The mass of all weights are listed in the
certificate. For small pressure steps, a box with small weights is optionally available.

Page 5
2. SPECIFICATION
2.1 General Specification
 Accuracy: ±0.05% of reading
 Engineering units: MPa, bar, psi, kg/cm2
 Piston & cylinder material: Tungsten carbide
 Increment mass set material: Carbon steel, 304 Stainless Steel (optional)
 Sealing ring material: Buna-N
 Fluid: Mineral oil; Sebacate (≥25MPa)；water (please contact with us in prior)
 Working ambient temperature: 15~25℃
 Gravity: Standard 9.80665 m/s2, or customize local gravity value
 Engineering units: MPa, bar, psi, kg/cm2
 Certificate: CNSA calibration traceable
 Pressure connector: M20x1.5 female, BSP or NPT is optional
 Dimension: 300 x 320 x 260 mm
 Tester net weight: 12kg (with metal case)

Page 6
2.2 Pressure range selectable sheet
Part Number
Pressure Range
Kn
Effective
Area
Mass Set
KY0.6
(0.04~0.6)MPa
0.1MPa/kg
1 cm
2
6 kg
KY1
(0.04~1)MPa
0.1MPa/kg
1 cm
2
10 kg
KY6
(0.1~6)MPa
0.5MPa/kg
0.2 cm
2
12 kg
KY25
(0.5~25)MPa
1MPa/kg
0.1 cm
2
25 kg
KY60
(1~60)MPa
2MPa/kg
0.05 cm
2
30 kg
KY70
(1~70)MPa
2MPa/kg
0.05 cm
2
35 kg
K
Y100
(1~100)MPa
2MPa/kg
0.05 cm
2
50 kg
2.3 Mass quantity and measuring range
Part Number
Pressure Range
Piston and
Bell
Mass quantity and measuring range
KY0.6
(0.04~0.6)MPa
0.04
MPa
10 x
0.05MPa
,
6 x
0.01MPa
KY1
(0.04~1)MPa
0.04
MPa
11 x
0.5MPa
,
4 x
0.1MPa
KY6
(0.1~6)MPa
0.
1
MPa
11 x
0.5MPa
,
4 x
0.1MPa
KY25
(0.5~25)MPa
0.
5
MPa
11 x
2MPa
,
5
x
0.5
MPa
KY60
(1~60)MPa
1
MPa
1
1
x
5MPa
,
4
x
1
MPa
KY70
(1~70)MPa
1
MPa
13 x
5MPa
,
4 x
1MPa
K
Y100
(1~100)MPa
1
MPa
9
x
1
0
MPa
,
1
x
5
MPa
,
2
x
2
M
P
a

Page 7
2.4 Instrument Outline
Remark: No priming hand pump and Float indicator for low pressure ranges (≤25MPa)

Page 8
3. SAFETY REQUIREMENTS
WARNINGS:
 Do not attempt to substitute common pipe fittings in place of original high pressure fittings used in the plumbing
systems on these instruments. Common pipe fittings are not rated for high operating pressure used in these
instruments, and the use of such fittings will void the warranty and may create a potentially dangerous condition.
Use any fittings, please contact with BALUNTECH in prior.
 Always wear safety glasses when operating instrument. A high pressure oil leak can cause permanent eye
damage.
 Do not attempt to operate the instrument in excess of the maximum pressure noted on the instrument.
 "NO SMOKING" signs are to be displayed in laboratories and on laboratory doorways whenever testers are
being used for instrument calibration. Because a leak in the tester's high-pressure line can release an explosive
mist of oil, proper fire extinguishers should be immediately available.
 Pre-load the tester's piston with weights before applying pressure to the gauge. Otherwise, shock from the
pressure can dislodge the piston retainer ring, allowing the piston to fly out of the tester at high velocity. The
operator could be seriously injured if standing directly over the instrument.
 Spinning the table counterclockwise and failing to load the table with weights before introducing pressure into
the instrument can cause the Table to spin off on some models, and the pressure nut to blow off, allowing the
piston to become a dangerous projectile.
 When a tester is used to test a gas or liquid line pressure, connecting tubing and fittings should be rated at a
pressure that is higher than the line pressure.

Page 9
CAUTIONS:
 If the test fluid or gas (oxygen) will be reactive with the oil in the tester's reservoir, testing must be performed
with an instrument supplied with synthetic oil. Before hydraulic oil is replaced, the tester must be thoroughly
cleaned, and the seals should be replaced to insure proper cleaning.
 Before bleeding pressure from the tester, the valve at the pressure source should be closed. The instrument's
pressure should then be slowly bled to atmosphere. If a vent valve is unavailable, the fitting at the tester should
be carefully and slowly loosened. This procedure is to create a small leak, minimizing the volume of oil that will
enter the interconnecting tubing.
 Hydraulic Fluid, such as: Shock absorber, brake fluid, or transmission fluid may not be substituted for the
hydraulic oil specified for the instrument.
 Never touch the cleaned piston with your bare hands. The natural dermal grease can cause a jamming of the
piston cylinder system.
 Never press the piston forcibly into the cylinder. Otherwise it is damaged.
 The weight should be handed with gloves. If fingerprints or other impurities are found on the weight pieces in
spite of this precaution, they can be removed with alcohol (spirit).
 The hydraulic oil should be changed whenever visible contamination is present.
 Waster oil must be disposed of according to legal requirements.

Page 10
4. SETTING UP THE DEADWEIGHT TESTER
4.1 Site requirements
 The room or onsite place in which the instrument is placed should have proper founding, no vibrations are
allowed during operation of the BL510 portable deadweight tester as this results in unpredictable errors.
 The BL510 portable deadweight tester should be placed on a rugged table which is rated for at least 140 kg
without deforming. The table should be horizontally leveled.
 Room temperature needs to be stable between 23 ± 2°C during the time the BL510 portable deadweight tester is
used to avoid uncertainties due to the thermal expansion coefficients of the piston cylinder and adiabatic effects
in the measuring system.
 Air movement around the BL510 portable deadweight tester should be avoided.

Page 11
4.2 Assembly the piston cylinder unit
Marking line for floating position (±10mm)
 As above picture, loose the bottom safety screw of piston cylinder unit.
 Check if the O-ring located in the center position of cylinder base the deadweight tester.
 Screw the whole piston cylinder unit in cylinder base of the deadweight tester. If necessary, uses wrench to tight
it till mechanical stop.
 Do not open the piston and cylinder unit by unprofessional people.
 In generally, the factory installed the piston and cylinder unit on the base before delivery.

Page 12
5. OPERATING THE DEADWEIGHT TESTER
5.1 Preparation
 Place the instrument on a firm level base.
 Check if the bubble level is in the center; if not, level the instrument with the 4 adjustable feet.
5.2 Pressure Transforming Media
 < 25MPa: Mineral Oil (Miglyol 812 Noil or equivalent oil with viscosity grade VG22)
 ≥ 25MPa: Sebacate Oil
5.3 Operation
1. Turn fine control screw press counter-clockwise till end of its stroke, open vent valve (oil drain valve).
2. Unscrew quick connector plug, screw the device under tester (DUT), opens cut-off valve.
3. Calculate the weight’s pressure and related quantities.

Page 13
4. Apply the pressure with priming hand pump up and down, till the strength through the hand pump level is felt
hard, close the vent valve (oil drain valve).
5. Put the mass on the mass plate carrier, manually rotate the table clock wisely, the rotate speed is about (30~60)
r/min. Use the fine control screw press to adjust pressure, the measuring pressure value on DUT can be read
while piston position is between -10mm and + 10mm where is exactly between two lines on piston cylinder unit
on the floating indicator mirror. (When test piston area, the piston positon should be pointed to 0 mm and then
read the value )
6. After read the 1st pressure test point, use fine control screw press to decrease the pressure, plus the other
calculated mass sets and increase the pressure again, rotates the table to test next pressure test point. The test
of rest of pressure points is same as this method.
7. For down process measurement, decline the pressure with fine control screw press slowly. Reduces the
calculated mass set, and rotate the table again, read the pressure value on device under tester. Repeat the
operation till all test points are finished.
REMARK: DO NOT OPEN THE VENT VALVE DURING OPERATION, OTHERWISE THE PISTON POD WILL
BE BROKEN!
8. After measurement, open the vent valve, fully way into the screw rod of pressure wheel pump, close the vent
valve, disassembly the DUT, screws the quick connector plug.

Page 14
6. MAINTENANCE
6.1 Cleaning and service tips
1. The O-rings on the cylinder base and connector, is easy to broken, please change it timely.
2. Do not open the piston and cylinder unit by unprofessional people.
3. Firmly tighten the knurled nut on the weight rod before transport to avoid abrasion of the weights and
loss of their mass.
4. If the weights are abraded in transport or are damaged by being dropped, they should be replaced.
5. Clean the weights with a soft brush rather than with a coarse or soiled cloth to avoid altering the mass
of the weights.
6. Avoid contaminating the instrument with dust and grit, preventing unnecessary wear of moving parts.
Contamination of the oil in the system will accelerate piston and cylinder wear and degrade instrument
accuracy.
7. Ensure that high-pressure fittings of the instrument are tight when operating the instrument indoors.
8. Remove the piston and cylinder for cleaning by unscrewing the adapter nut. If the nut is sealed to the
body with an O-Ring, it should only be finger tightened when replaced.
9. TRANSPORT THE INSTRUMENT WITH THE COVER IN PLACE. If the cover becomes damaged, it
should be replaced.
6.2 Oil changes
 Replace the oil if any contamination is suspected.

Page 15
 Corrosive contaminants in the oil may damage the piston and cylinder assembly.
 Fill the oil reservoir through the filler cap with mineral oil or sebacate (≥25MPa) before an instrument is
used for the first time. The oil level must be maintained above the lower end of the cylinder, or the gas
will bypass the oil. When field temperatures are extremely cold, fill the reservoir with SAE 10 non-
detergent motor oil or equivalent oil. Maximum sensitivity of the instrument to pressure requires that
the oil be "light" at the time of measurement.
 For the instrument to be sensitive, the metal-to-metal interface of its piston and cylinder is designed to
allow for the minor escape of oil past the piston to minimize friction and lubricate the piston. Therefore,
some leakage past the piston is normal and necessary. A moderate escape of oil can be controlled by
adding heavier oil. Excessive leakage or "blowing" of oil past the piston indicates excessive wear of the
assembly and requires replacement of the assembly. If the model and serial numbers of the instrument
are furnished, the piston and cylinder assembly and the weights can be replaced without need for
factory calibration.
 Replace hydraulic oil (do not use brake fluid, shock absorber, or transmission fluid) in the reservoir with
mineral oil or sebacate (≥25MPa) when the test fluid or gas (oxygen) will be reactive with the hydraulic
oil. For oxygen gauge test, recommend Baluntech water media deadweight tester.
6.3 Maintenance schedule
 Change oil: Every 6 months or as necessary
 Change O-ring: Every 6 months or as necessary
 Re-calibration: Every 2-5 years

Page 16
7. TROUBLESHIOOTING
Gas escapes past piston when used to determine unknown gas pressure.
 Insufficient oil in Reservoir Adapter. Shut off and bleed pressure from tester. Pump oil to adapter until
reservoir is full.
 Damaged Cylinder O-Ring. Unscrew the piston cylinder unit from cylinder base, replace O-Ring.
 Gas bubbles or blows into oil of center reservoir when determining unknown gas pressure.
 Damaged Cylinder O-Ring. Unscrew the piston cylinder unit from cylinder base, replace O-Ring.
Not sensitive to small weight changes when used to determine unknown gas pressure.
 Over-tightened cylinder cap nut. Unscrew cap nut, re-tighten only until snug.
 Dirty oil. Remove oil, clean reservoir with solvent, fill reservoir with clean oil.
 Damaged Piston. Remove piston & cylinder as per above "Damaged O-Ring" Clean with solvent. If
"Binding" is evident, replace with new Piston and cylinder unit.
 Cold weather makes standard oil too viscous. Replace standard oil with low temperature pour point oil.

Page 17
Pressure cannot be maintained when calibrating another pressure gauge.
 Air is drawn into pump because of insufficient oil in center reservoir. Unscrew Cap and check oil level in
reservoir. Add oil if necessary.
 Damaged cylinder adapter O-Ring. Unscrew the piston cylinder unit from cylinder base, replace O-Ring.
 Leakage through valve.
Excessive oil leakage at piston.
 Damaged cylinder O-Ring. Replace O-Ring.
 Oil too light. Check and remove fluid in reservoir if it is shock absorber or brake fluid. Replace with mineral
oil or sebacate.
 Worn piston & cylinder assembly. Replace with new Piston & Cylinder Unit.
Not sensitive and/or inaccurate operation during hydrostatic testing.
 Water emulsifying with tester oil.
 Best - Use synthetic oil instead of standard mineral oil. Satisfactory - Use oil water separator.
Remark: The specification in this user manual would be changed without notice.