DP Transmitter Range

1500 mm = 59 inches. I would recomend a 100 in H2O transducer. No need to go bidirectional. Just a 100 In H2O differential x-ducer.

the required one is to have a filled in diaphragm seal type transmitter for level measurement

+/-250in x 25.4mm per inch = _{<tap, tap, tap..>} +/-6350mm.

What is the liquid and its temperature?

The liquid is water and temp is 29 degC

Hi,

-250" to 250" of water capillary D/P transmitter will work fine for this application.

keep in mind that when this transmitter is installed and with the High and Low legs vented to atmosphere the transmitter is going to read negative differential.

For example if the distance between the High and Low legs is 60" the transmitter is going to read around negative 60" of water. The manufacture recommends that the transmitter is mounted half way between the taps, but most of the time we mount them at the bottom tap or where ever is accessible.

In your case let's say that the High side tap is located at the bottom of the tank and the Low side at the very top of the tank and the distance between them is 1500mm(59 inches) with both legs open to atmosphere the transmitter is going to read -59" of water(give or take -for explanation only-) that will be you zero level or LRV

To calculate 100 percent level or URV we'll multiply height time S.G. (1500X1) equals 1500mm(59"of water) we add 59" to our zero -59+59= 0 so our URV will be 0" of water.

This is probably more than what you wanted to know and I hope I didn't make it too confusing.

Thank you

Thanks for the detailed reply...

the transmitter is Diaphragm Seal ...Rosemount 1151 series and as the site requirements will call for the installation,then i guess the URV and LRV will be corrected and configured at site

The wet leg will be there all the time so i expect that with the proposed range,it can work.

<...the URV and LRV will be corrected and configured at site...>

If the instrument is adjusted at Site, any set-up record provided by the vendor will be invalid. Site would need to have a standardised test-set with which to set it up. It might be better to leave it alone, perhaps?

1151 Roemount transmitter model is replaced by 2051.

The tank is closed, but is it vented to the atmosphere?

Why a wet leg? on water?

Why a diaphragm seal? Is this a sanitary (pharmaceutical) application?

Diaphragm seals ALWAYS have temperature coefficient errors. I have numerous trend charts showing absolutely static (non-changing) tank levels cycling - high in the day, low at night due, up and down due to weather changes - due to the effect of temperature change on the diaphragm fill closed system.

Diaphragm seals should be used only when absolutely required for corrosion protection or Sanitary requirements because of the error inherent in temperature changes.

If this is an vented tank, why can't you run an impulse line? If you're in a northern climate, heat trace the impulse line and transmitter body for freeze protection.

An impulse line avoids the temperature errors of diaphragm seals.

This is a space constraint issue and the lines will be heat traced and insulated .

The tank is closed and non vented type