K-TEK Level Transmitter Abnormal Reading

1) Can the K-Tek float be physically pushed to zero and then recover? Is the indicated float level change showing an actual level change?

2) If the level is not changing, then the symptoms could be temporary loss of power.

What is the initialization process that the K-tek meter goes through when it powers up? Does the output start at zero and then work its way to the actual value? If you don't know, test it. Remove the power and watch what happens when it powers up. If the initialization process matches the phenomenon that you're seeing, then you need to figure out why the power is dropping out on a periodic basis.

Friend,

I can´t understand very good your question, but if both transmitters are going to zero and comeback to 50% and this same level is showed in the glass gauge maybe there is a process problem.

Now if it only the K-tek is changing its output without real level change, I agree with the point 2 of Iris, loss of power.

But, If this performance is showed every 30-40 minutes, My tendency would other problem.

Please, Can you tell us which kind of K-tek level transmitter(radar, Dp) are you using?

Regards
JP

Has the 30-40 minute restart anything in common with any other part of the plant which has heavy load, and may be causing restart, or interference with the signal. Or are there data acquisitions with a higher priority being collected around that frequency?

no , we don't have any thing same like being restart ...by the way below is data for K-Tek

Area classification - class I, Div2,

Fluid service - Olefin free isobutene

Transmitter - magnetic level gauge with magnetostrictive type gauge ,Integral meter K-TEK

Power supply - 24VDC Foundation fieldbus

Calibration range - 12500 mmH2O ,

in concern Mr.IRIS to initialization process that the K-tek meter goes through is first come 000 as and within second goes real level,,

level in gauge glass remain 50% & transmitter output goes live "0" to dcs for while & come back this continue happen after every 30-40 minute, here the link of we are using model type

http://www.ktekcorp.com/dnn20/Default.aspx?tabid=67&productID=1

Hello My name is Scott Cochran lead Service Engineer with K-TEK / ABB. I have noticed that this is FFB Protocol. Please let me know the type of Host system you are using and also the serial number of the two units. You can also reach me at 225-673-6100 Ext 189 CST. The problem description seems to be a possible loss of communication. What kind of error code or fault appears in your Host System? Voltage at transmitter? It is hard to know exactly without further information. Please give me a call if this is a time difference issue @ 225-328-0683 cell . I am available 24/7

What signal is the DCS getting?
4-20mA?
Foundation Fieldbus?

How long does the K-tek remain in its zero output state? 1 second? 10 seconds? 1 minute? 10 minutes?

Do you know this because someone stood at the tank and timed the zero fault with a stop watch, or are you looking at a DCS trend graph?

What is the logging (sampling) interval on the DCS?

Be aware a DCS can be set up to sample only every 1, 5, or 10 minutes on a slow moving tank level. What appears to be a 1 minute zero value on a trend graph could be the DCS sampling interval.

from AT200 Magnetostrictive Level Transmitter manual (page 16):
5.3.2. Electrical Considerations
Power Filter:
A Fieldbus segment requires a power conditioner to isolate the power supply filter and decouple the segment from other segments attached to the same power supply.

Has this been done?

Foundation Fieldbus instrumentation is very fussy about its power, with specs for ripple and the requirement for a power conditioner.

I suspect that something in the plant is causing periodic power "brown out" or power deviations to the device.

Anonymous poster, as Mr. Cochran points out this could be an FF communications issue. You really need to contact Mr. Cochran, as he suggests.

His email address is listed on this K-tek contacts page.

http://www.ktekcorp.com/dnn20/DesktopModules/images/SupportContacts.pdf