**DP Flow Transmitter Re-Range** : This tool is used to calculate the DP Flow transmitter revised flow with the following inputs: Existing DP, Existing Flow & Revised DP.

This tool is primarily used for orifice based flow meters. Also useful for flow transmitters which works on Differential Pressure applications.

Generally we calibrate our transmitter as per the datasheet of orifice. But sometimes the measured DP of transmitter will be out of range or more than maximum scale of DP then we have to re-range the DP flow transmitter.

For these applications we use the below mentioned formula to calculate the maximum flow of transmitter.

## DP Flow Transmitter Re-Ranging

This calculation tool is used to calculate the revised flow range of a DP Flow transmitter.

The formula for calculating the DP Flow Transmitter Re-Range value.

Where,

Existing DP = DP value as per orifice datasheet

Existing Flow = Flow value as per orifice datasheet

Revised DP = Actual DP value in the field

Revised Flow = Calculated transmitter flow max range.

Note:

1. The Existing DP & Revised DP must be in same units like bar, mbar, mmh20 etc.

2. The Existing Flow & Revised Flow must be in same units like m3/hr, t/hr etc.

Also See: Instrumentation Calculator

## 13 comments

I am instrument guy and i am very rarely found tools related to instrumentation. I am very happy to see these type of tools. Please update more with complex calculations like density measurement, Interface measurement, USM flow calculations etc.

I Just loved your site dude :love:

Hi. We have a flowmeters with instrument range 0 to 500 mbar and calib. Range 0 to 250 mbar for normal flow =10000kg/h but we need 10311 kg/h so we have to recalibrate it .please help me how i do it .i mean 0~250mbar should change to 0~? Many thanks

You should just change your scale !

Reading dp flow ,so long as your devices within the capability of the pressure device , everything is ok.

For mentioned ranges above is your remedy but for large differences you need to know your device limitation.

dear sir

i have one orifice plate concentric type and id is 25 mm.but i do not calculate Dp range please guide in LRV & URV range. how to calculate……….

Be careful this is for 4~20 ma not for fieldbus .

Dear Rahim, Thank you for the suggestions.

What’s the right way to re-range DP fieldbus “FF” transmitter?

Sir,

I Need Suggestion on Flow. Orifice D/P To Connected DP Transmitter With Sq.root Op.

Indicator also Need Sq.root Input or Linier In put.

Pls Explain sir.

Regards

Raju

What is the minimum static working pressure

Sir I’m instrumentation Engg I have do transmitter in condensate water line as per data sheet 1500 mmwc I puted urv range in transmitter but I’m not getting full flow as per pump discharge 110 m/3 hr only I’m getting 49 m3/hr so please suggest

if we re range the value… does the square root graph also change ?

Respected sir,

Pls give me solution. How to we calculate nm3/hr flow for different case. Like air, gas. Please give one note with example.