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Radar Level Transmitter Fluctuation
Guide Wave Radar Level Transmitter fluctuation
1 out of 1 members thought this post was helpful...

We are using 3 No Guide wave level transmitters (make: E&H) in fire water pump house diesel tank level monitoring. As per weekly once trial of Diesel Engine, Diesel level transmitters fluctuation happening. This fluctuation remains until transmitter sensor cleaning done.

Every week level transmitters fluctuation happening. Kindly advice to how to overcome this fluctuations.

Vimal Gupta

The Dielectric constant for Diesel is very low <3 as opposed to water ~80 so you won't get a very good echo. Is it possible to add a float to get a good echo?

Model No
What are you cleaning off?
Is there any foam or emulsion layer?
Quite frankly I thing radar is a bad choice.


A guided wave transmitter is not a good choice, no question.

No doubt a useful device, but it has more factors that can go wrong than some of the more traditional, and proven methods.

The coaxial probe is the one with the highest sensitivity.

Does your GWR transmitter have a coaxial probe? I'll bet it's a rod probe, the least sensitive style GWR probe.

By vimal Gupta on 1 April, 2017 - 2:36 am

Dear Sir,

Level transmitter Model Is FMP51 E&H Rod type Guided wave radar level transmitter.

Cleaning sense; we remove from flange and cleaned the sensor after that sensor reading ok. Inside close tank, i think vacuum will create on diesel consumption during diesel engine running.

I have one doubt, if vacuum creates then level transmitter may have problem. Tank has dedicated breather installed on roof of tank. If guided wave radar is not suggested, which transmitter is applicable for close type diesel application.

I think E&H have software that will look at the echo on the transmitter. It might show you something that is interfering with the signal.

I suggested earlier could you add a metal float to the rod. It would float up and down providing a good target for the radar. A flange mounted DP cell on the bottom of the tank would have been cheaper and reliable.

Is their any foam on the surface? Radar likes a well defined interface.
I don't follow why a vacuum would effect radar, could you explain that?

There is echo curve browsing software for EH GWR. I think you maybe able to download it also free from their website or you request it free from them. Then you can see how much strong is the echo received and also if the echo is lost so you can analyze exactly and see the behaviour. even you can record the echo as video for some time.

In case of the probe always need cleaning, so the rod type is the most suitable and maybe non-guided wave is more suitable in this case but your echo should be strong.