I am using Differential pressure transmitter calibrated with water (0-500 Pa) for my experiments. Now I am going to change the working fluid from water to aqueous glycerin. Shall I use the same DP transmitter for aqueous glycerin? or I need to calibrate the DP transmitter for aqueous glycerin?

 

Hi dyaha400 -

You are measuring DP - but for what outcome? Level, Flow, Density?
The specific gravity of water at standard conditions is 1.0.
The specific gravity of aqueous glycerin is not 1.0 - it depends on temperature and concentration - maybe 1.13 at 50% and 15°C?
Additionally - glycerin is normally quite viscous - depending on temperature and concentration viscosity may have an impact on DP.

So to answer your question - yes, you will need to adjust your calculations.

i.e.; With your range 0-500Pa I suspect you are measuring flow through some minor restriction?

It sounds to me like you are not calculating flow - but standardizing against a reference value.

You will need to recalibrate for your new solution - and remember to compensate as concentration and temperature vary.

Cheers,
PB

 

Hi PB,

Thanks for your reply.

I am measuring DP using DP transmitter and directly using it in final equation to get power loss.

The aqueous glycerin properties are specific gravity=1.09, dynamic viscosity =3.5 mPas.

You are asking me to re-calibrate the DP transmitter, but I am not find suitable standard pressure measurement device.

Can you please suggest any device and procedure for re-calibration?

with regards,
Dhayananth