Siemens SITRANS LUT400 Operating Instructions Manual page 13

11.5 Noise Problems ..................................................................................................................... 276
11.5.1 Determine the Noise Source ................................................................................................. 277
11.5.1.1 Acoustical Noise ................................................................................................................... 277
11.5.2 Non-Transducer Noise Sources ........................................................................................... 277
11.5.3 Common Wiring Problems .................................................................................................... 278
11.5.4 Reducing Electrical Noise ..................................................................................................... 278
11.5.5 Reducing Acoustical Noise ................................................................................................... 278
11.6 Measurement Difficulties ...................................................................................................... 279
11.6.1 Loss of Echo (LOE) ............................................................................................................... 279
11.6.1.1 LOE occurs when: ................................................................................................................. 279
11.6.1.2 If 2.4.3. Fail-Safe mA Value is displayed, check the following: ............................................ 279
11.6.2 Adjust Transducer Aiming ..................................................................................................... 279
11.6.3 Increase Fail-safe Timer Value ............................................................................................. 280
11.6.4 Install a Transducer with a Narrower Beam ......................................................................... 280
11.7 Fixed Reading ....................................................................................................................... 280
11.7.1 Obstructions in the Sound Beam .......................................................................................... 280
11.7.2 Nozzle Mountings ................................................................................................................. 281
11.7.3 Set the SITRANS LUT400 to Ignore the Bad Echo .............................................................. 281
11.7.3.1 If the Echo is Close to the Transducer.................................................................................. 281
11.7.3.2 Adjust the TVT to Ignore the Echo ........................................................................................ 281
11.8 Wrong Reading ..................................................................................................................... 281
11.8.1 Types of Wrong Readings .................................................................................................... 281
11.8.2 Liquid Splashing .................................................................................................................... 282
11.8.3 Adjust the Echo Algorithm .................................................................................................... 282
11.9 Transducer Ringing............................................................................................................... 282
11.9.1 Normal Ring Down ................................................................................................................ 282
11.9.2 Poor Ring Down .................................................................................................................... 283
11.10 Echo Profile Display .............................................................................................................. 283
11.11 Trend Display ........................................................................................................................ 283
12 Technical data ....................................................................................................................................... 284
12.1 Power .................................................................................................................................... 284
12.2 Performance ......................................................................................................................... 284
12.3 Interface ................................................................................................................................ 285
12.4 Mechanical ............................................................................................................................ 286
12.5 Environmental ....................................................................................................................... 287
12.6 Approvals .............................................................................................................................. 287
13 Dimension drawings .............................................................................................................................. 288
13.1 SITRANS LUT400 Dimensions ............................................................................................. 288
13.2 Cutout Dimensions (for Remote Panel Mount) ..................................................................... 289
A Technical reference ............................................................................................................................... 290
A.1 Principles of Operation ......................................................................................................... 290
A.1.1 Process Variables ................................................................................................................. 290
A.1.2 Transmit Pulse ...................................................................................................................... 290
SITRANS LUT400
Operating Instructions, 07/2019, A5E33329501-AC
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