Siemens Industry, Inc / IA / Process Instruments Level ... Measurement Products Basic Non-contacting Theories ... Changes in process conditions directly impact the signal strength

Restricted © Siemens Industry, Inc. 2015 All rights reserved. Answers for industry.

Level Measurement Products Basic Non-contacting Theories

Siemens Industry, Inc / IA / Process Instruments

Restricted © Siemens Industry, Inc. 2014 All rights reserved.

Page 2 Klee / PI Process Instrumentation

Which sailboat is closest? How do you know?



Now which sailboat is closest?



Non-contacting Technologies Ultrasonics and Radar

Echo Ranging and Time of Flight



Let’s take a look under the hood…



Ultrasonic Level Echo Ranging and Time of Flight

Sound travels at constant known velocity at a given temperature

52.65 mS 28.11 mS 31.95 mS 35.22 mS 38.55 mS 45.18 mS 41.99 mS 49.00 mS 55.12 mS 0.00 mS 3.02 mS 6.10 mS 9.80 mS 12.30 mS 15.10 mS 16.07 mS 19.19 mS 25.77 mS 22.55 mS 58.20 mS



Ultrasonic Level Echo Ranging Calculation

DISTANCE = VELOCITY x TIME

Speed of sound in air @68Fº is 1128ft/s

Time between sound

transmission and echo received

65.6 ft = 1128.6 ft/s x 58.2 mS

Divide by 2 to determine travel

distance one way 65.6 ÷ 2 = 32.8ft

Distance

Example: for a 58.2 millisecond time interval



Radar Level Echo Ranging Calculation

DISTANCE = VELOCITY x TIME

Speed of light is 300,000,000

mps

Time between sound

transmission and echo received

20 m = 300,000,000 mps x 66.67 nS

Divide by 2 to determine travel time one way

20 ÷ 2 = 10m Distance

Example: for a 66.67 nanosecond time interval



Level Space Distance

DIFFERENTIAL

Volume

FLOW

Siemens Non-contacting Level operations

Restricted © Siemens Industry, Inc. 2015 All rights reserved. Answers for industry.

Level Measurement Products Sonic and Process Intelligence




Siemens Intelligence Sonic and Process Intelligence

Sonic and Process Intelligence.

Setting Siemens apart.



Level reading example: If the empty distance is 50ft and distance measured by the device is 30ft then material level calculated is:

50ft – 30ft = 20ft

50ft

= 30ft

Transceiver or Transmitter

20ft

Level calculation from a distance measurement

OR OR

Known distance

Time of Flight The calculation of level



What are sonic intelligence and process intelligence?

Sonic intelligence and process intelligence are embedded firmware that provide: • Fast and easy product set-up • Repeatable, accurate and reliable level detection • Flexibility

• Sonic intelligence is used in our Ultrasonic devices • Process intelligence is used in our radar devices



Sonic and Process Intelligence for non-contacting level measurement

Non-contacting level measurement devices

Ultrasonic devices and Sonic Intelligence Radar devices and Process Intelligence

LUT400 SITRANS LU02 SITRANS LU10

HydroRanger MultiRanger

Probe LU Probe LR LR200

LR250/ LR260

LR560 LR460 The Probe



What sets us apart?

Experience • Over 40 years and 1 million applications worth of real-world field experience.

Process Knowledge Our Time Varying Threshhold (TVT) is Dynamic Works in 95% of all applications right from Quick Start without any tuning Adjustable to the applications needs



Siemens “Sonic & Process Intelligence” How it works – radar and ultrasonic echo profiles

1. The Pulse

2. The Return Signal

3. Form the Profile

4. Filtering

5. TVT

6. Echo Algorithms

7. Echo Selection



Break . Be back in 15 minutes



Changing Process Conditions

Siemens “Sonic & Process Intelligence”– Dynamic TVT



Changes in process conditions directly impact the signal strength Foam, Steam, Agitation, Dust

Siemens “Sonic & Process Intelligence” – Dynamic TVT



With a fixed threshold, as signal strength degrades, it is possible for the unit to lose sight of the material level entirely (Loss of Echo)





With a fixed threshold, as signal strength degrades, it is possible for the unit to lose sight of the material level entirely (Loss of Echo)


Our dynamic TVT adjusts itself with each shot maintaining a lock on the material level as the signal strength decreases




Siemens “Sonic & Process Intelligence” – Dynamic TVT and Foam

Low Frequency High Frequency

FOAM DENSE MEDIUM LIGHT



Installation Challenges – Obstructions

Split silo with supports

Narrow Wetwell

Agitator Blades



Echo Ranging Theory

Echo profile The receiver must remain off

during the signal transmission and ringdown

Since time is relative to distance, the ringdown time is commonly referred to as the blanking distance of the transducer

The return signal cause the crystal to begin vibrating again

This signal is sent to the receiver for processing

100dB

75dB

50dB

25dB

0dB

0ft 5ft 10ft 15ft 20ft 25ft

Transmit Return Pulse Signal



Echo Ranging Theory

Echo profile Time Varying Threshold (TVT) A reference to compare echoes at

different positions in time A far echo will be weaker because

sound has traveled a greater distance

An ideal TVT would have a slope equal to the attenuation of sound

100dB

75dB

50dB

25dB

0dB


Blanking Time Varying Distance Threshold (TVT Curve)

Transmit Return Pulse Signal



Echo Ranging Theory

Sonic Intelligence Echo Lock Window The width of the window is set by

the measure response parameter (P003)

Dampens false echoes outside of the window

Requires an echo outside the window to be present for five consecutive shots before it is considered a true echo

100dB

75dB

50dB

25dB

0dB



Transmit Return Echo Pulse Signal Lock Window



Echo Ranging Theory





100dB

75dB

50dB

25dB

0dB






Echo Ranging Theory





100dB

75dB

50dB

25dB

0dB






Siemens “Sonic & Process Intelligence” – Auto false echo suppression

1. The Pulse

2. The Object Return Signal

4. Form the Echo Profile

5. Apply Filtering

6. TVT Profile

7. Apply Echo Algorithms

10. Echo Selection

3. The Material Return Signal

8. Echo Selection

9. Run Auto False Echo Suppression

Typical obstructions:

Pipes

Weld seams

Ladders

Agitators

Support structure

Beams

Wires

1. Determine distance to material

2. Subtract ~0.3 meters or 1 foot

3. Enter this value as the “Suppression Range”

4. Perform a “Learn”



Siemens “Sonic & Process Intelligence” – Manual TVT shaper

The Manual TVT Shaper can be accessed using any one of the supported interfaces (varies by device)

Allows the user to manually adjust the TVT up or down, as the application dictates.



Siemens “Sonic & Process Intelligence” – Multi-shot sampling/ number of shots

Preset number of shots varies from product to product

Increasing the shots improves confidence and reduces noise floor, however, it may also slow measurement reporting.



Siemens “Sonic & Process Intelligence” – Filtering

Spike Filter

Narrow Echo Filter *Be careful when using the Narrow Echo Filter in liquids

applications as the true echo may be as narrow as the false echoes.

Narrow Echo Spikes



Siemens “Sonic & Process Intelligence” – ALF algorithm

Echoes are evaluated by A, L, and F components (Area, Largest and First).

Scores/ confidences are assigned to each echo based on these 3 criteria

The highest score from the 3 criterion is selected for each echo.

The echo with the largest net score is selected as the true echo.

There are many variants of ALF, the most common being bLF (Best of Largest and First.

Only evaluates Largeness and Firstness – highest combined score wins



Siemens “Sonic & Process Intelligence” – Quick start

For many of our products the quick start is a simple set of parameters needed to commission the unit.

Our Next Generation products use simple, Quick Start wizards locally at the unit, with the Hand Programmer, SIMATIC DTM or SIMATIC PDM.



For Internal Use Only / © Siemens AG 2011. All rights reserved.

Thank You For Your Attention


Tim Bulbuk Siemens Application Engineer Siemens Process Instruments (517) 304-8018 [email protected]

Siemens Industry, Inc / IA / Process Instruments Level ... Measurement Products Basic Non-contacting Theories ... Changes in process conditions directly impact the signal strength

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