Home » Open and Closed Tank Level Calculations
Formulas Level Measurement

Open and Closed Tank Level Calculations

Open Vessel Level Calculation

Open tank : Zero-Based Direct Mount Application

Zero-Based Direct Mount Application

In above example, transmitter installed exactly at HP tapping point i.e. at 0 % Level

Calibration Range

LRV or 4mA point = 1.1 * 0 = 0 inH2O

URV or 20mA Point = Head = 1.1*50” = 55 inH2O

Cal. Range = 0 to 55 inH2O

Open Tank : Non-Zero-Based Direct Mount Application 

Non-Zero-Based Direct Mount Application

In above example, transmitter installed point and Tank Zero Percentage level are different.

Calibration Range

LRV or 4mA point = Head1 = 1.1*10” = 11 inH2O

URV or 20mA Point = Head2 = 1.1*50” = 55  inH2O

Cal. Range = 11 to 55 inH2O

Open Tank : Non-Zero-Based Remote Mount Application 

Non-Zero-Based Remote Mount Application

Calibration Range

LRV or 4mA point = Head1 = 1.1*10” = 11 inH2O

URV or 20mA Point = Head1 + Head2 = (1.1*10”) + (1.1*50”) = 66 inH2O

Cal. Range = 11 to 66 inH2O

Closed Tank Level Calculation (Wet Leg)

Closed Tank : Zero-Based Direct Mount Application 

Closed Tank Zero-Based Direct Mount Application Wet leg

In above example, transmitter installed exactly at HP tapping point i.e. at 0 % Level

Calibration Range

LRV or 4mA point =  Phigh – Plow = 0 – Head1 = 0 – (1.2*70”) = -84”H2O

URV or 20mA Point = Phigh – Plow = Head2 – Head1 = (1.1*50”)] – (1.2*70”) = -29”H2O

Cal. Range = -84 to -29 inH2O

Closed Tank : Non-Zero-Based Direct Mount Application 

Closed Tank Non-Zero-Based Direct Mount Application

In above example, transmitter installed point and Tank Zero Percentage level are different.

Calibration Range

LRV or 4mA point = Phigh – Plow = Head2 – Head1 = (1.1*10”) – (1.2*70”) = -73”H2O

URV or 20mA Point = Phigh – Plow = (Head2 + Head3) – Head1

= [(1.1*10”) + (1.1*40”)] – (1.2*70”) = -29”H2O

Cal. Range = -73 to -29 inH2O

Closed Tank : Non-Zero-Based Remote Mount Application

Closed Tank Non-Zero-Based Remote Mount Application

Calibration Range

LRV or 4mA point = Phigh – Plow = Head2 – Head1 = (1.1*10”) – (1.2*80”) = -85”H2O

URV or 20mA Point = Phigh – Plow = (Head2 + Head3) – Head1

= [(1.1*10”) + (1.1*50”)] – (1.2*80”) = -30”H2O

Cal. Range = -85 to -30 inH2O

Also Read: Basics of Hydrostatic Level

Related Articles

Paddle Wheel Level Switch Principle

S Bharadwaj Reddy

Magnetic Level Indicator Principle, Limitations, Installation and Calibration

S Bharadwaj Reddy

Gas Flow Formulas

S Bharadwaj Reddy

Formula to Calculate 3-15psi from 4-20mA Current

S Bharadwaj Reddy

Probe Type GWR Level Transmitter Working Animation

S Bharadwaj Reddy

Siemens Differential Pressure Transmitter Calculations (Flange Type)

S Bharadwaj Reddy

5 comments

Karuna May 6, 2016 at 1:39 am

Easy Calculations & in Understandable way. Thanks Bharadwaj sir.

Reply
imran May 20, 2016 at 6:57 am

Sir how to mount dot in for vaccum tank level measurement already we are using magnetic level gauge which works on magnetostrictive principle.

Reply
Teguh June 1, 2016 at 4:45 am

Thank you this a simple calculation

Reply
Murthy Gsn June 23, 2016 at 2:55 am

It’s really use full & simple calculations sir.Thank you very much sir.

Reply
Ramin September 10, 2017 at 6:03 am

I am so happy finding this learning web site. Suggested to my friends as well. Using daily to improve my skills. Thanks for this web site creator.

Reply

Leave a Comment

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More