3
Flow rate, m /h
100
10
1
0,1
0,01
0,0010,01 0,1 110 100 1000
Pressure loss, MPa
Figure 1.3 – Pressure loss nomogram for KARAT-520 flowmeters
КАRАТ-520-20КАRАТ-520-20
КАRАТ-520-80КАRАТ-520-80
КАRАТ-520-25КАRАТ-520-25
КАRАТ-520-32КАRАТ-520-32
КАRАТ-520-40КАRАТ-520-40
КАRАТ-520-50КАRАТ-520-50
КАRАТ-520-65КАRАТ-520-65
1.3.2.Output signals parameters
Flowmeters of all design variants have 2 galvanically isolated pulse
outputs for transmission of measured values in the form of pulse
signalswiththespecifiedpulseweight(table1.2).
Pulsesignalhasthefollowingcharacteristics:
nminimumpulse-repetition interval...........................................…62;
npulse duration, ms ……………....................………................….31;
nvoltageinoutputcircuit,V,notmorethan………............…..…….50;
nminimumcurrent,providedin anoutputcircuit,mA.......................2;
nmaximumswitching current inanoutput circuit, mA…................10.
Flowmeter of KARAT-520-ХХ-3 design version has 2 analog elements
with current signal parameters according to GOST 26.011(“Measuring
and automation devices. Input and output current and voltage continu-
oussignals”):
nOutputcurrent,mA…....................................................…......4–20;
nSupply voltage, V ..................................................…....……12–36;
nMaximumloadresistance, Ohm…........................................…100.
FlowmetersofKARAT--520-ХХ-1,KARAT-520-ХХ-2designversions
withdigital outputRS-485, M-Bushavethe outputsignalparameters,
whichmeet therequirements, mentionedinstandards forthepresent
interfaces.
1.3.3.Powersupplycharacteristics
Inaccordancewith design version (table 1.1) flowmeters can be sup-
plied both from internal and external power sources according to de-
signversion.
Flowmeters of design version (it.1.2) are supplied from built-in lith-
ium battery of “C” dimension type with voltage equal to 3.6V ± 0,2V
and capacity equal to 7.2Ah. Battery life accounts to not less than 4
yearsofflowmetercontinuousrunning.
0
Flowmetersof , ,,designversionsaresuppliedfromexternaldirect
current source with output voltage from 12 to 36V. The output current
ofapowersourceshouldcorrespondtothefollowingcharacteristics:
nitshouldbenotlessthan100mAfor and designversions;
nnotlessthan50mAfor designversion;
nnotlessthan10mAfor4designversion.
1.3.4.Hydrauliccharacteristics
Diagrams of pressure loss dependence on the flow rate in flow tubes
fordifferentdimensiontypesaregivenonfigure1.3
1 2 3 4
1 2
3
