Level 1 - Pressure 2RMT Training - 05 /98

5

Example: ZeroZero--Based Based Direct MountDirect Mount Application

What is the Calibration Range?

XMTR

H

Head

Open Vessel Level CalculationOpen Vessel Level Calculation

L

100%

0%

50

S.G = 1.1

GP = 1.1 * 0

= 0H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)GP = Head

= 1.1*50

= 55 H2OCal. Range = 0 to 55H2O

Level 1 - Pressure 2RMT Training - 05 /98

6

Example: NonNon--ZeroZero--BasedBased Direct MountDirect Mount Application

What is the Calibration Range?

XMTR

H

Head2

Open Vessel Level CalculationOpen Vessel Level Calculation

L

100%

40

S.G = 1.1

GP = Head1= 1.1*10

= 11H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)GP = Head2

= 1.1*50

= 55 H2OCal. Range = 11 to 55H2O

0%10 Head1

Level 1 - Pressure 2RMT Training - 05 /98

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Example: NonNon--ZeroZero--BasedBased Remote MountRemote Mount Application

What is the Calibration Range?

XMTR

H

Open Vessel Level CalculationOpen Vessel Level Calculation

L

100%

50

S.G = 1.10%

10

Head2

GP = Head1= 1.1*10

= 11H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)GP = Head1 + Head2

= (1.1*10) + (1.1*50)

= 66 H2OCal. Range = 11 to 66H2O

Head1

Level 1 - Pressure 2RMT Training - 05 /98

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Zero Elevation: Example (for a DP span of 100 H2O)Wet Leg : Calibrated Range -20 H2O to 80 H2O

0% 100%

Zero Supression: Example (for a DP span of 100 H2O)Dry Leg : Calibrated Range 20 H2O to 120 H2O

0% 100%

0 H2O

20 H2O

-20 H2O

0%/LRV of Dry Leg

0%/LRV of Wet Leg

True Zero (Measured)

ZeroSuppressed

ZeroElevated

Zero Suppression & ElevationZero Suppression & Elevation

Level 1 - Pressure 2RMT Training - 05 /98

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XMTR

HL

Ullage or Vapor

Head2

S.G = 1.1

Closed Tank Level Calculation (Wet Leg)Closed Tank Level Calculation (Wet Leg)Example: ZeroZero--BasedBased Direct MountDirect Mount Application

What is the Calibration Range?S.GWetLeg=1.2

50

100%

0%

Head1

4mA pt? (at 0% level)

20mA pt? (at 100% level)

Cal. Range = -84 to -29H2O

70

DP = Phigh - Plow= 0 - Head1= 0 - (1.2*70)= -84H2O

DP = Phigh - Plow= Head2 - Head1= (1.1*50)] - (1.2*70)= -29H2O

Level 1 - Pressure 2RMT Training - 05 /98

10

XMTR

HL

Ullage or Vapor

S.G = 1.1

Closed Tank Level Calculation (Wet Leg)Closed Tank Level Calculation (Wet Leg)Example: NonNon--ZeroZero--BasedBased Direct MountDirect Mount Application

What is the Calibration Range?S.GWetLeg=1.2

100%

Head1

DP = Phigh - Plow= Head2 - Head1= (1.1*10) - (1.2*70)= -73H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)DP = Phigh - Plow

= (Head2 + Head3) - Head1= [(1.1*10) + (1.1*40)] - (1.2*70)= -29H2O Cal. Range = -73 to -29H2O

10 Head2

Head340

0%

70

Level 1 - Pressure 2RMT Training - 05 /98

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XMTR

HL

Ullage or Vapor

S.G = 1.1

Closed Tank Level Calculation (Wet Leg)Closed Tank Level Calculation (Wet Leg)Example: NonNon--ZeroZero--BasedBased Remote MountRemote Mount Application

What is the Calibration Range?S.GWetLeg=1.2

100%

Head1

10

Head3

0%

70

Head2

DP = Phigh - Plow= Head2 - Head1= (1.1*10) - (1.2*80)= -85H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)DP = Phigh - Plow

= (Head2 + Head3) - Head1= [(1.1*10) + (1.1*50)] -(1.2*80)= -30H2O Cal. Range = -85 to -30H2O

50

Level 1 - Pressure 2RMT Training - 05 /98

12

The transmitter must be mounted level with or below the lowest tap to ensure positive pressure at the transmitter.

Diaphragm seals for tanks under VACUUM

DP = Hside - Lside= (L*SGp + h*SGf ) - (H+h)*SGf= L*SGp - H*SGf

Dist. Betw. Taps = H

h

H L

L

CapillaryRemote Seal

1.0 psia(27.7

inH2O) DP Transmitter

SGp SGf

H

Level Calculation with Remote SealsLevel Calculation with Remote Seals

Level 1 - Pressure 2RMT Training - 05 /98

13

HL

30S.G = 1.1

Level Calculation with Remote SealsLevel Calculation with Remote Seals

100%

Head1Head3

0%

7050

S.Gfill=0.9

Head2

Example: Double RemoteDouble Remote Seal ApplicationWhat is the Calibration Range?

DP = Phigh - Plow= Head2 - Head1= (0.9*30) - (0.9*100)= -63H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)DP = Phigh - Plow

= (Head2 + Head3) - Head1= [(0.9*30) + (1.1*50)] -(0.9*100)= -8H2O

Cal. Range = -63 to -H2O

Level 1 - Pressure 2RMT Training - 05 /98

14

Example: To measure change in density

What is the Calibration Range?

Max. Allowable S.G = 0.2

Ullage

Pbottom

Ptop

L H

Remote Seal

10 ft

Dist. Betw. Taps = 10 ft = 10 x 12= 120

SGp 1.1 to 1.3

Density Calculation with Remote SealsDensity Calculation with Remote Seals

SGf = 0.95

DP = 120 * (SGp - SGf)= 120 * (1.1 - 0.95)= 18H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)

Cal. Range = 18 to 42H2O

DP = 120 * (SGp - SGf)= 120 * (1.3 - 0.95)= 42H2O

Level 1 - Pressure 2RMT Training - 05 /98

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Application Example: To determine % of interface of Liquid A with respect to Liquid B.

What is the Calibration Range?

Dist. Betw. Taps = 10 ft = 10 x 12= 120

Vapor

0%

100%

SG1= 1.1

SG2= 1.3

Pbottom

Ptop

L H

Remote Seal

10 ft

Liquid A

Liquid B

SGf = 0.95

DP = 120 * (SG1 - SGf)= 120 * (1.1 - 0.95)= 18H2O

4mA pt? (at 0% level)

20mA pt? (at 100% level)

Cal. Range = 18 to 42H2O

DP = 120 * (SG2 - SGf)= 120 * (1.3 - 0.95)= 42H2O

Interface Calculation with Remote SealsInterface Calculation with Remote Seals