Pulsar SLUDGE FINDER 2 Service Manual

PULSAR ULTRA SERIES
SLUDGE FINDER 2 SERVICE MANUAL (FIRST EDITION Rev 2)

June 2017
Part Number M-920-S-001-1P

COPYRIGHT

© Pulsar Process Measurement Limited, 2000 – 17. All rights reserved. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language in any form
without the written permission of Pulsar Process Measurement Limited.

WARRANTY AND LIABILITY

Pulsar Process Measurement Limited guarantee for a period of 2 years (for the integrator), and 1 year (for the
transducer), from the date of delivery that it will either exchange or repair any part of the product returned to
Pulsar Process Measurement Limited if it is found to be defective in material or workmanship, subject to the
defect not being due to unfair wear and tear, misuse, modification or alteration, accident misapplication or
negligence.

DISCLAIMER

Pulsar Process Measurement Limited gives nor implies any process guarantee for the product, and shall have
no liability in respect of any loss, injury or damage whatsoever arising out of the application or use of any
product or circuit described herein.

Every effort has been made to ensure accuracy of this documentation, but Pulsar Process Measurement
Limited cannot be held liable for any errors.

TECHNICAL ENQUIRIES

Please contact Pulsar Process Measurement Limited for technical support.

COMMENTS AND SUGGESTIONS

If you have any comments or suggestions about this product, then please contact:

Pulsar Process Measurement Limited
Cardinal Building
Enigma Commercial Centre
Sandy’s Road
Malvern
Worcestershire
WR14 1JJ
United Kingdom
Tel: [phone] (International [phone])
Fax: [phone] (International [phone])
Web Site: http://www.pulsar-pm.com
e-mail: [e-mail] (general information)
e-mail: [e-mail] (product support)

CONTENTS

About Service Parameters....................................................................................................................................... 1

Echo Profile Overview ............................................................................................................................................ 2

Sludge Finder 2 Service Parameters....................................................................................................................... 7

P021 Set Distance ........................................................................................................................................... 7

P043 Breakpoint.............................................................................................................................................. 8

P044 Slope ..................................................................................................................................................... 11

P046 Persist Count (Direct Access Only) .................................................................................................... 11

P047 Outside Count ...................................................................................................................................... 12

P883 Gate Expand (Available in Stability Menu under 1997)................................................................... 12

P050 Negative End ....................................................................................................................................... 13

P051 Margin Enable ..................................................................................................................................... 13

P052 End Margin .......................................................................................................................................... 14

P067 Choose Peak ........................................................................................................................................ 15

P068 Measure Percentage ............................................................................................................................. 16

P079 Use Gate ............................................................................................................................................... 17

P088 Hard Default ........................................................................................................................................ 17

Service Alarm ................................................................................................................................................ 17

P194 Date ...................................................................................................................................................... 17

P195 Interval.................................................................................................................................................. 17

P196 STD Zeroes .......................................................................................................................................... 18

P197 STD Code ............................................................................................................................................ 18

P198 Phone Number ..................................................................................................................................... 18

P199 Reset ..................................................................................................................................................... 18

P884 Trace Update ........................................................................................................................................ 19

P885 Threshold Percentage .......................................................................................................................... 19

P886 Minimum Threshold ........................................................................................................................... 19

P887 Wipe Interval ....................................................................................................................................... 20

P888 Motor Persist ........................................................................................................................................ 20

Sludge Finder 2 Troubleshooting ......................................................................................................................... 22

Page 1

About Service Parameters

The following parameters can only be accessed via the following passcode
552621 and can be used to modify Echo Processing Algorithms in particularly
arduous applications.

Further parameters allow changes to parameters specific to communications and
other hardware functions.

Care and caution should be exercised when changing any of these parameters
and any such changes should only be undertaken by, or under the guidance, of
an experienced Service Engineer.

Direct Access.

In order to access parameters directly use the following procedure.

Some parameters are not part of the menu system and can only be accessed

directly. To do this use the cancel key until there are no digits in the main
display then key in the parameter number and press enter.

Page 2

Echo Profile Overview

The Digital Adaptive Tracking of Echo Movement, is a powerful algorithm

unique to Pulsar’s ultra range of products. Care should always be taken when
adjusting and analysing echo profiles, if in doubt, please contact Pulsar technical
department.

There are no ‘typical’ echo traces for Sludge Blanket applications, the echo
returns vary widely with the type of application and the concentration levels of the
Sludge.

The screen shot below is a Secondary Clarifier approx 70% full.

The y axis indicates signal strength and the x axis is distance.
The black shape is the echo profile of the sludge.
The blue line indicates the measuring point.

Page 3

The Components of the Echo Profile Display.

Threshold
Line

Measuring
Window

Measuring Line

Echo Profile

Tank
Floor

Page 4

How to interpret the echo profile screen.

The first echo that is reflected back to the transducer is from the top of the sludge
blanket, the second echo with the sharper leading edge is the echo reflected back
from the bottom of the tank.

Page 5

Problematic Echo Profiles.

This echo profile is typical of what you would see if the transducer was out of the
water

No echo returns.
There is no sludge present the echo return is from the bottom of the tank

Page 6

The transducer is surrounded by material in flight, or, the blanket level is high
enough to be surrounding the transducer.

Multiple echoes, the unit is receiving multiple signal returns, either from different
densities of Sludge Blanket, or, an object in the water.

Page 7

Sludge Finder 2 Service Parameters

P021 Set Distance

Use this parameter to tell the unit which of the echoes is the correct one in a
situation where there are multiple echoes, or there is a large amount of ’material
in flight’ in the area above the interface.
Establish the distance from the face of the transducer to the interface in
measurement units and then enter this value into P21.
The unit will lock onto the true echo and attempt to suppress any unwanted echoes
in the settling zone above the interface leaving the correct echo untouched.

Example. The settled sludge is at 4m distance but, there is an echo from a ‘rag’
layer at 2.5m, go to parameter 21 and enter 4m thus informing the unit which of
the echoes it is required to measure, the unit will then auto-adjust to this echo.

Default = 0.00

Page 8

P043 Breakpoint

The gain starting point in meters, for signal amplitude decay compensation. Used
in conjunction with P44, to establish fixed gain levels. See table below for details.

Application Type SBR
Application Type Secondary

Default = Application Dependant

Application Type

SBR

Industrial

Primary

Secondary

P43 Breakpoint (metres)

1.0m

1.5m

1.5m

1.0m

P44 Gain (slope/angle)

5

10

10

15

P050 Negative
End Setpoint.

Values Min = 0m Max = 99.9m

Page 9

In addition to the operator adjustable signal amplitude decay compensation there
is also an existing layer of suppression programmed into the Sludge Finder
software. This suppression becomes active when SBR’s or Secondary are chosen
as the application type.

The suppression works by applying negative gain compensation to the settle zone
in front of the leading edge of the gate as indicated below.

If Industrial or Primary is chosen as the application type this compensation is not
present. However, in instances where there are large amounts of settling material
in front of the true echo, as shown below by the Blue Trace (the Raw Echo Signal
Return), and the operator adjustable signal amplitude decay compensation is not
sufficient, it may be necessary to alter the application type to increase signal
suppression.

Application Type

SBR

Industrial

Primary

Secondary

Settle zone signal
suppression active

No

Yes

Yes

Yes

Page 10

The compensation works as explained below.

Page 11

P044 Slope

This sets the angle of the positive time varied gain line. That is, the amount of
gain applied. See the explanation of P43 for details.

Values Min = 0
Max = 1000

P046 Persist Count (Direct Access Only)

This parameter determines the number of processed echoes the unit will need to
see moving in the same direction before the display reading is updated. This is to
help prevent the displayed reading from fluctuating whilst inside the gate. Sludge
echoes are constantly changing shape and in order to prevent the reading from
‘hunting’, the echo has to move in the same direction for 5 counts in order for it to
be seen as a trend and update the reading.

Values Min = 1
Max = 1000

Default = Application Dependant

Default = 5

Page 12

P047 Outside Count

This parameter determines the number of processing cycles, or transducer ‘shots’,

that any valid echo must be seen outside of the gate before the gate will move and
allow the new echo to be processed. This will prevent any unwanted update, or
false readings being given due to the intermittent appearance of echoes from
devices such as scrapers.

Values Min = 1
Max = 5000

P883 Gate Expand (Available in Stability Menu under 1997)

This parameter is closely associated with the Outside Count as part of the
Damping parameters designed to make the reading more stable. When the Outside
Count has expired and the Gate is moving towards a new target then it expands at
a rate of 0.1m after every cycle.

Values Min = 0
Max = 99.99

Default = 10

Default = 0.1m/min

Page 13

P050 Negative End

The point at which, the negative gain line intersects the 0.0m distance y axis.
This parameter determines the angle at which the rate of near signal amplitude
suppression, (gain attenuation), is applied, over a distance starting at the gain
breakpoint . See the explanation of P43 for details.

Values Min = -999
Max = 999

P051 Margin Enable

This parameter is associated with P52 End Margin.
1 switches the feature on
0 (off) is the default value
Values Min = 0
Max = 1

Default = 80

Default = 0 off

Page 14

P052 End Margin

The End Margin sets a boundary within which the Secondary Negative Gain
applied from the front of the gate is released.

Sometimes during periods of rain or high flow the interface is disturbed, this can,
under certain conditions, cause the unit to read incorrectly low.

When the event is over and the interface is re-forming at a higher level the
negative gain applied at lower levels is preventing the correct echo from being re­established.

When the ‘End Margin’ is set to on and the echo falls to a level below the level
set in P52, then the Secondary Negative Gain applied from the front end of the
gate is not applied and the unit has a chance to re-establish itself on the correct
echo.

Values Min = 0.00m
Max = 99.99m

Note * The unit as does not apply negative gain at the front of the gate as a default

when no echoes can be seen within the system span (i.e. no ‘Normalised’ echo

trace).
If this is required, then set P51 = 1 and P52 = 0
*Versions 111E and above.

Default = 0.2m

Page 15

P067 Choose Peak

1 = Area
2 = Largest
3 = First
4 = Last

Example, in the example below the tank bottom is at 5.9m, therefore there are
three distinct echoes within the unit span.

Default = Transducer Dependant

Page 16

P068 Measure Percentage

This parameter determines where the blue distance marker line intersects the echo
profile. Factory set to 80% of the total height of the leading edge echo.
This determines the measured distance.

Values Min = 0
Max = 100

Default = 80%

Blue line
positioned 80%
up the leading
edge of the echo

Page 17

P079 Use Gate

The gate should always be set to on for a Sludge Blanket application. Otherwise
the reading could become unstable.

Options 0 = No
1 = Yes

P088 Hard Default

P88 allows both User and Service parameters to be reset to their Factory Default
values.

N.B. P930 Factory Defaults will allow the user to reset only those parameters
which are accessible via the User Passcode (Default 1997), but will not reset any
parameters which are accessed via the Service Code 552621. Thus ensuring any
adjustments carried out by Service personnel are protected.

Options: 0 = No
1 = Yes

Service Alarm

P194 Date

The day the alarm is set to operate. Factory set to 365 days passed the current date
set into the unit.

P195 Interval

The Interval in days before the unit will next go into alarm. The unit will display a
warning that a service interval is approaching 7 days before the event (starting at
midday)

Default = 1 (on)

Default = 0

Default = e.g. 01/01/16

Default = 365

Page 18

P196 STD Zeroes

The number of zeroes in the STD Code e.g. 1 (for 01684 891371)

P197 STD Code

The STC Code e.g. 1684 (for 01684 891371)

P198 Phone Number

The Phone Number e.g. 891371 (for 01684 891371)

P199 Reset

Access the parameter and enter 1=Yes to reset the alarm

Default = 0

Default = 0

Default = 0

Default = No

Page 19

P884 Trace Update

This parameter takes 10% of a new echo profile and adds it to the existing profile
to produce a new echo trace.

Values Min = 0
Max = 100

P885 Threshold Percentage

This parameter auto set the threshold level by taking an average level of the
process echo return and multiplying by 120%.
Values Min = 0

Max = 300

P886 Minimum Threshold

The yellow trace indicates the minimum threshold i.e. the yellow trace will not
fall below this value
Values Min = 0

Max = 99

Default = 10%

Default = 120%

Default = 10db (100mv)

The threshold level is dynamic and is worked out by multiplying the average
height of the black trace within the span by 120%. As the signal return
increases so the threshold level will increase. And, as the signal level
decreases, so the threshold level will decrease. But, not below its minimum
value of 100mv.

Page 20

P887 Wipe Interval

The elapsed time between wiping cycles, on initiation of a wipe cycle the wiper
arm will perform three sweeps of the transducer face to keep it free from material
build up.

Values Min = 0.1
Max = 99999

P888 Motor Persist

Default = 20 mins

Default = 5

Page 21

The number of times the voltage to the wiper motor has to fall below the fail set
point before a wiper fail indication is initiated.

Values Min = 0
Max = 999999

To initiate a wipe from the run mode in order to check the wiper functionality the
F5 hot key should be pressed.

Application Type Auto Parameter Settings

Parameter

SBR

Industrial

Primary

Secondary

Breakpoint in
mm

1.0m

1.5m

1.5m

1.0m

Slope

5

10

10

15

Fill Damping in
mm

200

50

20

20

Empty
Damping in mm

200

100

20

20

Settle Zone
Signal
Suppression

No

Yes

Yes

Yes

Page 22

Sludge Finder 2 Troubleshooting

This section deals with some simple fault finding procedures.
Initial Checks.
Check that the unit has been wired correctly, care must be taken to ensure that the

mains voltage and the transducer cables are connected in the right place.
Ensure any protective transit covering has been removed from the transducer face

and wiper blade.
Check that the transducer has been installed in the correct position and that it has

a clear as possible shot at the sludge blanket. Avoid areas where there may be
flow disturbance, excessive material in flight, air bubbles or gassing from the
blanket and objects under the surface of the material that could interfere with the
ultrasonic beam.

If the transducer is mounted on a rotating bridge install the transducer on the
leading edge. Most scrapers tend to follow round behind the bridge and will only
disturb the blanket after the transducer has passed by.

Ensure the blanket is within range of the transducer.
If you are programming the unit for the first time, or re-commissioning the unit, it

would be good practice to default the unit back to factory settings so the
instrument would be as it was when it was originally despatched. Once you do this
any parameters already programmed will be lost, so make a note of them before
starting the procedure, if appropriate.

To initiate a factory default, go to parameter P88 and enter 1.

Page 23

If, after switching on the unit, the LCD displays one of the following messages:
“No Xducer”, “Xducer Fault”, “L.O.E.”, “Failed Safe” or “Wiper Fault”,
then you should check the transducer voltages and wiring.

Page 24

The voltages shown above should be present at the unit and the junction box if
one is used.
The voltages come from the control unit to the transducer, the return signal is
current based and difficult to check in the field.
First remove the cable from the unit and check the voltages are there at the
terminals.
If the voltages are ok without the cables attached but change when the wires are
connected, then you have a wiring problem.
Connecting the wires incorrectly or shorting them out should not damage the
transducer.
Often the transducer extension cables are not the same colour as on the
transducer integral cables so the voltages need to be checked at the local junction
box to ensure they are there and connected correctly.
It is always preferable to commission the unit when there is a Sludge Blanket
present. If possible, establish where the blanket is before attempting to
commission the unit.

If after you have programmed your unit, the reading is not correct observe the
Echo Profile Display and ascertain if an Echo is present.

If an Echo is present but the reading is incorrect look for the following faults on
the Echo Profile Display.

Page 25

IF THE UNIT IS READING TO LOW.

Page 26

The display is now correct and the gate in the right place measuring the sludge.

IF THE UNIT IS READING TOO HIGH.

The unit will read high when the material in flight in the ‘Settle Zone’ is

sufficiently high so that the echoes returned from this area are bigger than those
coming back from the actual Sludge Blanket.
This is not an uncommon problem in settlement tanks and the unit has service
parameters that can reduce the signal return in this area whilst maintaining the
returns from the true echo.

Material in Flight
Echo

Sludge
Blanket Echo

Bottom
Echo

Page 27

The application is a secondary settlement tank, P43 the Gain Setpoint has been re­set to 1.5m to increase the negative gain applied to the profile, and a P21 initiated.
The resultant echo profile is now correct.