德國國家計(jì)量院標(biāo)準(zhǔn)裝置

德國國家計(jì)量院(FTB)熱水標(biāo)準(zhǔn)裝置概述

峭National

primary

standard

for

volume

flowrates

ofwater.Flow-rate:

3

~

1000

m3/h.Temperatures:

3

~

90°CThe

maximum

Reynold"s

number

5.5x106.Two

independent

weighing

procedures,

to

obtainhighly-valuable

measurement

resultsExpanded

combined

uncertainty

of

0.04%.@及洛大孽概in述Testfacilityextendsover2floors.Twomeasuringsectionsof25mlength.Constantleveltankis11minheight.CollectiontankV=40m3.StoragetankV=65m3.Waterflowcanbesuppliedinfourdifferentoperationmodes四種工作模式

&玄MiFrequency

controlled

circulation

pumps

up

to

1000

m3/h.Constant

level

tank

for

flow

rates

up

to

80

m3/h,

for pulsation-free

water

flow

at

a

constant

static

pressure.Pressure-based“single”mode

for

flow

rates

up

to

200 m3/h.二一compWraetsesredofaitrheatstporreasgseurteasnkupistoex5p.e5lblaerd.pulsation-free

byPressure-based

“continuous”

mode

for

flow

rates

up

to 1000

m3/h

at

pressures

between

1.5

bar

and

5.5

bar.-

The

expelled

water

of

the

storage

tank

is

refilled

continuouslyusing

frequency

controlled

pumps

between

the

collection

and

thestorage

tank.其它特性

&夫MlWatertemperatureenteringmeasuringsectionsvaries lessthan100mKduring2hours.Additionallythedensityandtheconductivityofthewate ismeasured.PipediametersDN80toDN400一flandgoeusblmeiswmaaltlcphiopfe;lessmsootthhaend5i0nnpemr.surfaces;anda一fullTyhidsevaellopwesdtthuerwbautleerntflfolwowtoprfofrimlaen.undisturbed,Velocitydistributioncanbemeasuredvia windowchambersusingaLaser-Doppler-Velocimeter; measuringvolume<100pminmaximumdimension靜態(tài)稱重法Theweighingtank(V=20m3)mountedonfour weighingplatforms.Thebalancecanbecalibratedwithinlessthan60sec. byanautomatedloadingandunloadingprocedure.36massstandards(560kgeach)isusedtodetermine thecalibrationcurveofthebalanceForthestaticmeasurementthemassofthewaterinthe weighingtankisdeterminedwithin50grams.TheinletoftheweighingtankconsisWofasteelplate with250drainpipes,inordertoensurelowanddefined momentumtransferfromthewaterflowingintothe weighingtank.雙換向器結(jié)構(gòu)

&玄泰會Ontopoftheweighingtankaretwodivertersofdifferen sizes.ToavoidevaporationlossesduringthefillingtimeToallowthedeflectionoflargevolumeflowrateswitha minimumofmomentumtransferinshortesttimes.Theswitchingprocesstakesapproximately1second.Repeatabilityoftheswitchingprocessisbetterthan13ms.\/ \/Beforethefillingprocess,providingtheweighingtank withairofwelldefinedtemperatureandhumidity.Duringthefilling,humidityandtemperatureofexpelled airfromtheweighingtankiscontrolled.動態(tài)稱重法

&玄泰會Besides

static

weighing

procedure,

the

weighing

system can

be

used

in

a

dynamic

procedure.Diverter

is

avoided,

weight

of

chosen

mass

standards

is replaced

by

the

same

amount

of

water

during

the measuring

time.For

this

purpose

the

readout

frequency

of

the

weighing cells

is

increased

up

to

40

HeWhereas

each

readout

of

each

cell

is

time-stamped within

an

uncertainty/Of

less

than

0,7

ms.To

avoid

influences

from

thermally

driven

air

flow

in measurement

hall,

it

is

planned

to

build

up

a temperature

stabilized

containment

for

the

whole weighing

system.德國國家計(jì)量院(PTB).http://www.ptb.de/indexen.html PTBisthenationalmetrologyinstitute;highesttechnicalauthorityundertheFederalMinistryofEconomicsandStaffs:1800Structure:Ninescientificandtechnicaldivision^subdividedintomorethan100sectionsandprojectsAnnualbudget:130millionEuro.Taslks:Rjimilameinrtlalsoff ftoreconomy,metrologyforsociety,,imtanisiUimollafciiisHistorical:Foundedin1887PTB

DivisionsMechanics

and

AcousticsElectricityChemical

Physics

and

Explosion

ProtectionOpticsPrecision

Engineering9.Ionizing

RadiationTemperature

and

Synchrotron

Radiation/cs

an8.MedicalPhysi dMetrologicalIniationTechnologyScientific-technical:Cross-sectionalTasksDivision

1

and

division

7:1MechanicsandAcousticsDivision1.1Mass1.2SolidMechanics1.3Kinematics1.4GasFlow1.5LiquidFlow1.52:NationalStandardforLiquidFlowMeasurement1.6Sound1.7AppliedAcoustics7Temperature&SynchrotronRadiation7.1X-rayMetrologywithSynchrotronRadiation7.2RadiometrywithSynchrotronRadiation7.3DetectorradiometryandRadiationThermometry7.4Temperature7.5CryophysicsandVacuumphysic-7.6Heat/ \—WorkingGroup7.61:ThermalEnergyMeasurement—IB.TTechnisch-WissenschaftlicheInfrastrukturBerlinWorking

Group

7.61Conformity

assessments

of

EC

type

examination

and

certificates

for the

design

of

heat

meters

or

sub-assemblies

according

to

MID, module

B+F,

B+D,

H1Type

approval

for

cold

meters

or

sub-assemblies

according

to

TRK7.2Responsible

for

80%

of

approvals/conformity

assessments

for heat

meters

in

Europe.Plays

most

of

the

time

the

leading

role

in

all

relevant

national

and international

committees.Calibration

of

flow

rate

sensors

for

cold,

warm

and

hot

water

in

the temperature

range

3

QC

to

90

QC

for

flow

rates

between

6

l/h

and 1000

m3/h

with

water

as

heat-conveying

fluid7Electrical

calibration

of

calculators

for

heat、and

cold

meters bv

means

of

thermal

energy

simulation

in

the

range

between

1QC

and

200

QC,

flow

range

between

6

l/h

and

1000

m3/h

andtemperature

difference

range

between

3

K

and

200

K,

range

ofpower

from

13.6

W

up

to

236,000

KWWorking

Group

7.61占^夫泰會Advise

of

the

industry,

supervisory

calibration

authorities

andconsumers

onfundamentals

of

the

metrology

of

thermal

energy,

volume

and

flow

rate

of cold-,

warm

and

hot

waters

as

well

as

water

glycol

mixtures—

application

of

thermal

and

solar

energy

metrologyInspection

of

heat

cost

allocators

by

the

responsible

administrative

bodies

.metrological

inspections

of

testing

facilities

for

heat

meters

andsubassembli