Hydronix Hydro-View HV02 User manual

Hydro-View
User Guide
Refer to Page 13 for Calibration Procedure when used in
Batch Weigher system Applications
Hydronix part number: D0022
Revision: 1.06
Revision date: 12 June 2007

COPYRIGHT
Neither the whole or any part of the information contained in nor the product described in this
documentation may be adapted or reproduced in any material form except with the prior written approval
of Hydronix Limited hereinafter referred to as Hydronix.
© 1996 Hydronix Limited
7 Riverside Business Centre
Walnut Tree Close
Guildford
Surrey
GU1 4UG
United Kingdom
All rights reserved
CUSTOMER RESPONSIBILITY
The customer in applying the product described in this documentation accepts that the product is a
programmable electronic system which is inherently complex and which may not be completely free of
errors. In doing so the customer therefore undertakes responsibility to ensure that the product is properly
installed commissioned operated and maintained by competent and suitably trained persons and in
accordance with any instructions or safety precautions made available or good engineering practice and
to thoroughly verify the use of the product in the particular application.
ERRORS IN DOCUMENTATION
The product described in this documentation is subject to continuous development and improvement. All
information of a technical nature and particulars of the product and its use including the information and
particulars contained in this documentation are given by Hydronix in good faith.
Hydronix welcomes comments and suggestions relating to the product and this documentation.
This documentation is intended only to assist the reader in the use of the product and therefore Hydronix
shall not be liable for any loss or damage howsoever arising from the use of information or particulars in
or any error in or omission from this documentation.
AKNOWLEDGEMENTS
Hydronix, Hydro-Probe, Hydro-Skid, Hydro-Mix, Hydro-View and Hydro-Control are Registered
Trade Marks of Hydronix Limited.
Author: R.E.B. Holland B.Eng. C.Eng. MIEE

HYDRO-VIEW USER GUIDE D0022 REV 1.06 3
Table of contents
Table of contents ................................................................................................................................................ 3
Introduction ......................................................................................................................................................... 9
System overview................................................................................................................................9
Scope of this document .....................................................................................................................9
Organisation of this document ...........................................................................................................9
Applications of Hydro-View with Hydronix moisture sensors ..........................................................10
A batch weighing system ...........................................................................................................11
Batch weighing calibration procedure ............................................................................................................. 13
Calibration........................................................................................................................................14
Dry Bucket method ..........................................................................................................................15
Method .......................................................................................................................................15
A batch mixing system ..................................................................................................................................... 17
A continuous process.................................................................................................................19
Hydro-View quick start ..................................................................................................................................... 21
Hydro-View front panel ....................................................................................................................21
Display contrast adjustment.......................................................................................................21
Keypad .......................................................................................................................................21
Soft key legends.........................................................................................................................22
Moisture display page......................................................................................................................22
Max / Min % display ...................................................................................................................23
Help facility.......................................................................................................................................24
Hydro-View main menu ...................................................................................................................24
Trend display page ..........................................................................................................................25
Changing operating values ..............................................................................................................27
Adjusting set-points .........................................................................................................................28
Material in use..................................................................................................................................29
Advanced user options and configuration....................................................................................................... 31
Sensor calibration ............................................................................................................................31
Sensor set-up menu ........................................................................................................................32

4 HYDRO-VIEW USER GUIDE D0022 REV 1.06
Output set-up menu ........................................................................................................................ 33
Sensor diagnostic display ............................................................................................................... 34
Audible Alarm.................................................................................................................................. 34
Material mode ................................................................................................................................. 34
RS232 usage .................................................................................................................................. 35
RS485 usage .................................................................................................................................. 35
Data log rate.................................................................................................................................... 35
Station number................................................................................................................................ 35
Number of slaves ............................................................................................................................ 35
Communications diagnostic page ................................................................................................... 36
Input 1 / Input 2 use ........................................................................................................................ 36
Language selection......................................................................................................................... 37
Factory default settings ................................................................................................................... 37
Sensor set-up ............................................................................................................................ 38
Output set-up............................................................................................................................. 38
Sensor calibration...................................................................................................................... 38
Set-point set-up ......................................................................................................................... 38
Other parameters ...................................................................................................................... 39
Suggested working values .............................................................................................................. 40
Sensor set-up ............................................................................................................................ 40
Output set-up............................................................................................................................. 40
Sensor calibration...................................................................................................................... 40
Set-point set-up ......................................................................................................................... 41
Other parameters ...................................................................................................................... 41
Calibration and sampling techniques .............................................................................................................. 43
Recommendations for best performance........................................................................................ 43
Equipment required......................................................................................................................... 44
Taking the samples ......................................................................................................................... 44
Batch mixer system sampling method ...................................................................................... 44

TABLE OF CONTENTS
HYDRO-VIEW USER GUIDE D0022 REV 1.06 5
Continuous system sampling method........................................................................................45
Drying the samples ..........................................................................................................................45
Recommendations for best performance...................................................................................45
Calculating the moisture percentage ...............................................................................................45
Entering results into the Hydro-View ...............................................................................................46
What happens with your results ......................................................................................................46
Grouping channels ........................................................................................................................................... 49
Group moisture variables.................................................................................................................49
Group moisture display....................................................................................................................49
Effect of communications errors on grouped systems ....................................................................50
Example - a twin bin grouped system using RS232........................................................................51
Example - a four bin grouped system using RS485 ........................................................................52
Installation......................................................................................................................................................... 55
Power supply connections ...............................................................................................................55
Adjusting the Hydro-View mains operating voltage ...................................................................56
Field connections.............................................................................................................................56
Sensor Connections – Hydro-Probe II.............................................................................................57
Installation guidelines.................................................................................................................57
Connecting the Hydro-Probe II to the Hydro-View ....................................................................57
Sensor Connections – Hydro-Probe I..............................................................................................58
Analogue output connections.....................................................................................................59
Digital input connections ............................................................................................................60
Relay output connections...........................................................................................................61
Material selection using Digital I/O ............................................................................................61
Protection from lightning strikes.......................................................................................................63
Troubleshooting ...............................................................................................................................64
Factory test display ....................................................................................................................64
Installation problems ..................................................................................................................65
Sensor installation faults..................................................................................................................66
Sensor characteristics................................................................................................................67

6 HYDRO-VIEW USER GUIDE D0022 REV 1.06
Using Hydro-View serial ports ......................................................................................................................... 71
RS232 serial port ............................................................................................................................ 71
RS485 serial port ............................................................................................................................ 72
Installation of RS485 module ....................................................................................................72
RS485 connections ................................................................................................................... 72
RS485 termination..................................................................................................................... 72
Data log mode................................................................................................................................. 73
Batch print mode ............................................................................................................................. 74
ASCII Hex mode ............................................................................................................................. 75
Scope ........................................................................................................................................ 75
Physical connection................................................................................................................... 75
Line signalling information......................................................................................................... 75
Basic frame format .................................................................................................................... 75
Frame types .............................................................................................................................. 76
Request frame types (‘command set’) ...................................................................................... 77
Timing constraints ..................................................................................................................... 78
ASCII Hex protocol examples ................................................................................................... 78
Appendix........................................................................................................................................................... 79
Access codes .................................................................................................................................. 79
Electromagnetic Compatibility Directive - 89/336/EEC................................................................... 79
Index ................................................................................................................................................................. 81

TABLE OF CONTENTS
HYDRO-VIEW USER GUIDE D0022 REV 1.06 7
List of figures
•Figure 1 - Batch weighing example.................................................................................................11
•Figure 2 - Batch mixing system.......................................................................................................17
•Figure 3 - Continuous mixing process ............................................................................................19
•Figure 4 - Hydro-View front panel ...................................................................................................21
•Figure 5 - Moisture display..............................................................................................................22
•Figure 6 - Help facility .....................................................................................................................24
•Figure 7 - Main menu ......................................................................................................................24
•Figure 8 - Trend display ..................................................................................................................26
•Figure 9 - Selecting parameters......................................................................................................27
•Figure 10 - Changing a value..........................................................................................................27
•Figure 11 - Changing options..........................................................................................................28
•Figure 12 - Sensor diagnostic display.............................................................................................34
•Figure 13 - Communications diagnostic .........................................................................................36
•Figure 14 - Sensor calibration line ..................................................................................................47
•Figure 15 - Group moisture display.................................................................................................50
•Figure 16 - Twin bin grouped system..............................................................................................51
•Figure 17 - Four bin grouped system..............................................................................................53
•Figure 18 - Panel mounting the Hydro-View...................................................................................55
•Figure 19 - Hydro-View mains transformer.....................................................................................56
•Figure 20: Connecting the Hydro-View to a Hydro-Probe II ...........................................................57
•Figure 21 - Sensor extension cable connections............................................................................58
•Figure 22 - Hydro-View rear panel..................................................................................................58
•Figure 23 - Hydro-View main circuit board .....................................................................................59
•Figure 24 - Analogue output wiring .................................................................................................60
•Figure 25 - Digital inputs .................................................................................................................60
•Figure 26 - Internal/external excitation............................................................................................60
•Figure 27 - Relay output schematic ................................................................................................61
•Figure 28 - Material selection using digital I/O................................................................................62
•Figure 29 - Factory loop-back test wiring........................................................................................65
•Figure 30 : Using test blocks...........................................................................................................68
•Figure 31 - RS232 serial port..........................................................................................................71
•Figure 32 - RS485 interface............................................................................................................72
•Figure 33 - RS485 module circuit board .........................................................................................73

8 HYDRO-VIEW USER GUIDE D0022 REV 1.06
Note: This manual references older versions of Hydro-Probe Sensors which have now
been superseded by the Hydro-Probe II. Hydronix recommends that all new
installations should use the latest available sensor cable, which should be
connected to the Hydro-View according to the instructions in the Hydro-Probe II
User Guide.

HYDRO-VIEW USER GUIDE D0022 REV 1.06 9
Introduction
System overview
The Hydro-View provides display and control-system interface facilities in an easy-to-
apply form for a single channel of moisture measurement using any of the moisture
sensors from the Hydronix range.
Key features include...
Hydronix sensor input including power supply source for sensor.
0-10Vdc or 4-20mA analogue output (link selected option) with working range scaled
from front panel.
Graphic display provides large characters for legibility and 'chart-recorder' displays of
sensor measurements.
RS232 serial port built in for communication to external systems or printer.
Plug-in RS485 multi-drop serial port module (extra-cost option).
Two digital inputs that may be configured for batch averaging, input filtering and
material level functions.
Sensor fault or out of range alarm relay output.
Two programmable set-point relay outputs.
Panel mounting model HV02 has 146x98mm facia dimensions with 140x92mm panel
cut-out. Overall depth including IEC connector is 205mm
Scope of this document
This guide describes Hydro-View model HV02 and associated options as indicated on the
rear panel label. Earlier versions of the Hydro-View do not contain all the features of the
HV02 and you should refer instead to the appropriate guide.
Organisation of this document
This guide is organised into the following sections...
Section Readership Description
Introduction All Orientation.
Hydro-View quick
start
All How to operate the Hydro-View front panel to
select displays, change working values etc.
Advance user
options and
configuration
Engineer How to configure the Hydro-View for a particular
application.
Calibration and
sampling
techniques
Supervisor &
Engineer
How to take samples of the material in use and
obtain results for calibrating the Hydro-View unit.
Grouping
channels
Engineer How to use multiple moisture sensors to compute
average values.
Installation Engineer How to install the Hydro-View in a control panel
and connect it to your control system.
Using Hydro-View
serial ports
Engineer How to configure and operate the Hydro-View for
use with RS232 and RS485 communications.

APPLICATIONS OF HYDRO-VIEW WITH HYDRONIX MOISTURE SENSORS
10 HYDRO-VIEW USER GUIDE D0022 REV 1.06
Applications of Hydro-View with Hydronix moisture sensors
The Hydro-View is used in conjunction with any of the moisture sensors from the Hydronix
range. Applications of the sensors normally fall into one of the following categories...
Where the average moisture content of a batch of material is required, the material
passing over the sensor only once during the batch. An example of this is in the batch
weighing of materials out of a storage bin with the moisture sensor (normally a Hydro-
Probe but possibly also a Hydro-Skid) mounted in or close to the outlet of the bin. This
type of application is referred to as a Batch Weighing application in this manual.
Where the moisture content of batch of material is measured continuously with the
material being recycled over the sensor, which in this case would normally a Hydro-
Mix. An example of this is a batch mixing application, where the homogeneity of the
batch is important. This type of application is referred to as a Batch Mixing application
in this manual.
Where the moisture content of a continuous stream of material is required. The
material passes the face of the sensor only once, but the moisture value is then used
as a feedback signal in a control loop. An example of this would be a Hydro-Skid
sensor mounted on the output conveyor of a continuous mixing system. This type of
application is referred to as a Continuous process in this manual.
Each of these categories of applications would require the use of different facilities and
settings within the Hydro-View.
The selection of appropriate Hydro-View facilities and interfacing to external equipment is
essential in obtaining the best performance from your Hydronix moisture measurement
system - inappropriate choice of the operating conditions is the biggest single cause of
poor performance.
Examples of these three categories are described below. These may be used as a guide
in developing your own systems although the applications of the Hydro-View are not
limited to these applications. The examples show the minimum configurations required
and in general do not show variations in the use of interfacing techniques, which are
described elsewhere.

INTRODUCTION
HYDRO-VIEW USER GUIDE D0022 REV 1.06 11
A batch weighing system
A typical example of a batch weighing system involving a moisture measurement point (in
this case a Hydro-Probe) at the output of the storage bin is shown in Figure 1.
The Hydro-View is interfaced as follows...
⇒Feed a signal to a digital input on the Hydro-View indicating when the gate is open.
This signal can be derived either from a limit switch on the gate or from an auxiliary
contact on the Open gate output in the batch control system, whichever is most
convenient. Configure this input as an Average/Hold input (see Input 1 / Input 2
use on page 36).
⇒Connect the Hydro-Probe sensor to the Hydro-View in the standard way.
⇒Connect the analogue output to the batch computer and set the output variable to
AVERAGE. The output range should be set according to the working moisture
range of the material; for most concrete batch applications, the default values of 0
and 20% are appropriate.
Refer to Installation later in this document for wiring details.
You may be tempted to short-cut this approach in some of the ways described below - if
you do this, you are unlikely to achieve satisfactory results and Hydronix cannot provide
technical support under these circumstances.
Recommendations for best performance
ALWAYS make use of the average/hold facility. Even if your batch computer is computing
the average moisture value in the batch, you will still need to display the average unscaled
•Figure 1 - Batch weighing example

APPLICATIONS OF HYDRO-VIEW WITH HYDRONIX MOISTURE SENSORS
12 HYDRO-VIEW USER GUIDE D0022 REV 1.06
input reading for calibration purposes which can only be done by providing the
average/hold input as described.
ALWAYS position the sensor so that the moisture value used is representative of the batch
being weighed. Generally, this means positioning the sensor as close to the point of
weighing as possible, within the constraints of ensuring sufficient material covers the
sensor.
ALWAYS perform the weight correction ‘on the fly’, towards the end of the same weighing
cycle. Some batch systems use the moisture value from one batch to correct the next
sequential batch - this is not adequate, as there may be large batch to batch changes in
moisture content. In some situations this can lead to the system performance actually
being worse when the moisture value is used.
ALWAYS ensure that the storage bins are managed correctly. Running out of material
during a batch may lead to errors in the reading, even though out of range readings are
not included in the average computation.
ALWAYS ensure that you are getting a meaningful input to the Hydro-View - there is little
point wasting time performing calibrations on the system if the sensor is covered by
stagnant material or is otherwise subject to inconsistent material flow. Verify this first
using the trend recorder display, which is a convenient way of observing the material
passing the probe.
ALWAYS use additional sensors where several gates are used - you should not assume
that the moisture content of the material flowing out of both gates is the same - it will not
be. The results of several Hydro-View units can be combined by use of the serial ports -
see Grouping channels (p49) for further details.
NEVER attempt to use the NOW reading to correct weights - the moisture content during a
batch can change quite dramatically. We have observed variations between 6% and 16%
during a single batch - the average value computed by the Hydro-View on the same batch
was accurate (compared with a desiccation test on a large sample of the batch) to within
0.2%.
NEVER attempt to use the displayed value for manual input into a batch computer for
weight correction if it is possible to interface directly. This relies on an operator to input the
value, which at best will be one batch behind and at worst will never be done.

BATCH WEIGHING CALIBRATION PROCEDURE
HYDRO-VIEW USER GUIDE D0022 REV 1.06 13
Batch weighing calibration procedure
The procedure detailed below will enable the Hydro Probe, when connected to a Hydro View,
to be used with confidence and accuracy. Ultimately, the accuracy of the system will only be as
accurate as the method of sampling and drying. Therefore great care must be taken when gathering
and drying samples.
The Hydro View is provided with factory default values stored in memory. These default
values are for initial installation set-up and allow the system to be used ‘’straight from the box’’. To
accurately calibrate the system, two samples of aggregate are required with at least 2-3% moisture
(minimum of 1%) difference and the aggregate flowing in the dynamic state. On initial installation, it
can be difficult to obtain two different moisture

CALIBRATION
14 HYDRO-VIEW USER GUIDE D0022 REV 1.06
⇒Reconnect power to the Hydro View
Calibration
Read this section completely before starting any calibration.
⇒Log into the system using access code 336.
⇒Select Unscaled Input from the main menu. This display will be used to display the readings
required for calibration.
The following operation of collecting samples may require two or more people.
Collecting a sample.
⇒Open the bin gates to discharge a batch.
If the system does not automatically select the average function then close the switch connected to
the Hydro View as the bin gate opens and open the switch as the gate closes..
⇒While the batch is discharging collect two to three kilogram of aggregate which accurately
represent samples of the complete batch. Place this in the container or bags and seal.
⇒Record the Average Unscaled Input displayed on the Hydro-View before the next batch is started.
The Average Unscaled Input will remain frozen on the display until the start of next batch.
Drying the sample to calculate the moisture content.
⇒Thoroughly mix the sample and remove approximately 1 Kg for drying. Reseal the container.
⇒Accurately weigh the this sample, record this as A
⇒Dry the sample until all traces of moisture have bean removed. This can be done by repeatedly
weighing the sample between heating until three consecutive weightings are the same. Take great
care not to lose any of the sample by careless stirring. Loosing only a few grains will make the test
invalid. Record this weight as B.
⇒Calculate (A-B)/B, this is the moisture content of the sample.
⇒Repeat the drying sequence for another 1kg removed from the sample above.
If the moisture is different by more than 0.1% then one of the samples was not dried out
completely and the test has to be restarted.
⇒Record the average of the two readings.
Hydro View Rear connector
13
14
16
17
Connect a single pole rocker
switch across terminals 13 and 14
Connect a wire link across
terminals 16 and 17

BATCH WEIGHING CALIBRATION PROCEDURE
HYDRO-VIEW USER GUIDE D0022 REV 1.06 15
Inputting the calibration into the Hydro-View
Unscaled I/P 2 and moisture 2 must always be of a higher moisture content than Unscaled I/P 1 and
Moisture 1. If the factory default figures for Unscaled Input 1 and Moisture 1 are displayed and the
new moisture calibration figures are higher than the displayed Unscaled input 2 and moisture 2, then
the displayed Unscaled Input 2 and moisture 2 should be transferred into Unscaled Input 1 and
Moisture 1 and the new figure entered as Unscaled Input 2 and Moisture 2.
⇒Select Sensor Calibration from the Hydro View main menu.
⇒Input the material table number for the material code to be calibrated.
⇒Enter the new calibration figures.
Before exiting the calibration check that the calibration makes sense !
The M value displayed at the bottom of the display should be in the range 0.3 - 0.6. If it is outside this
range the figures input should be checked and the method of collecting and drying the sample
checked. If all is correct with the data then contact Hydronix for further assistance.
⇒Exit the calibration page by pressing the softkey as follows
A pop up menu will appear asking you to confirm the changes
⇒Press
⇒When a moisture content with a difference of 2-3% is available repeat from 1 above.
Dry Bucket method
This procedure can be used on initial calibration when the silo can not be re- loaded with aggregate
with moisture levels with a difference of 2-3%. It will provide a working system which can be fully
calibrated at a later date.
Equipment required
Plastic Bucket
Dry aggregate of approximately 1% moisture, enough to fill the bucket. This can be dried prior to
arriving on site. A sample should be tested as above. If not dry to 0.5-1.5% then the aggregate
should be dried once more.
Method
⇒Place the Hydro Probe in the centre of the bucket with the ceramic facing the centre and tilted to 10
degrees. The bottom of the probe should be 20mm from the base of the bucket.
⇒Carefully pour the aggregate around the probe as lightly as possible. Do not compact the
aggregate but TAP the bucket gently on the ground twice.
⇒On the Hydro View select from the main menu Unscaled input and record the Unscaled input
value.
⇒On the Hydro View select from the main menu Sensor calibration and enter the reading for the
recorded Unscaled input into Unscaled input 1.

DRY BUCKET METHOD
16 HYDRO-VIEW USER GUIDE D0022 REV 1.06
⇒Dry a sample of the aggregate in the bucket and record it’s moisture content, enter this figure into
the Sensor calibration page as Moisture one.

HYDRO-VIEW USER GUIDE D0022 REV 1.06 17
A batch mixing system
A typical batch mixer system using the Hydro-View is shown in Figure 2. Two interfacing
schemes are illustrated...
‘One-shot calculation’ approach
The first scheme uses the analogue output to transmit the moisture content to a batch
computer then calculates how much water to add to the mixer. This is an approach used
in the Hydronix Hydro-Control IV system, which performs both measurement and water
addition.
Improved performance in this type of system can often be obtained by using the
Coarse/Fine digital input to select a ‘tighter’ filtering algorithm a few seconds prior to
taking the measurement. The filter constants are set up in the Sensor Set-up menu.
‘Dribble-feed’ approach
The second scheme, which is useful only when there are few time constraints on the mix
cycle, uses the set-point outputs to add water to the mixer. The water is added fairly
slowly in this case, since it must be mixed evenly before the reading is valid. To speed
things up a little, the second set-point output could be used to provide a coarse water feed
in the case of very dry materials.
Recommendations for best performance
ALWAYS site the Hydro-Mix sensor in the most appropriate place for the mixer design. The
position chosen should ensure that the sensor is covered by sufficient material at all parts
of the mixer cycle and is not in an area prone to build up of waste material, which would
lead to erroneous readings. General advice on this can be found in the Hydro-Mix sensor
data sheet and by contacting your Hydronix supplier.
•Figure 2 - Batch mixing system

18 HYDRO-VIEW USER GUIDE D0022 REV 1.06
ALWAYS pay attention to the sensor filter requirement. Static pan mixers in particular
create large air pockets in the mix, which cause large ‘spikes’ in the sensor reading. The
digital filter built into the Hydro-View is quite effective at removing these and the constants
given in Suggested working values (p40) should be adequate for most pan mixer
applications.
ALWAYS ensure that the sensor reading has stabilised within the required tolerance band
before taking a reading. This indicates that the mix is homogeneous. This may mean
extending the mixing time accordingly although excessive mixing times should be avoided
to prevent damage to the mix.
ALWAYS position the sensor so that it is easily inspected without removal i.e. so that it can
be clearly seen from an inspection door.
NEVER reduce the digital filter constants so low (e.g. 0.01V) as to make the signal
response very slow - although this will produce a stable reading, it will probably be the
incorrect reading. In particular, watch for mix cycles following production gaps being
excessively wet which is a clear sign that the time constant is too long.
NEVER place the Hydro-Mix sensor directly below a water or material feed into the mixer.
You should give the materials as much time as possible to mix before it is ‘seen’ by the
sensor.
NEVER calibrate until you are satisfied with the signal from the sensor and that the mixing
times are appropriate - otherwise you are wasting your time.

A BATCH MIXING SYSTEM
HYDRO-VIEW USER GUIDE D0022 REV 1.06 19
A continuous process
A typical example of a continuous process is shown in Figure 3.
In this case, a continuous mixer is supplied with material to be wetted to a pre-set
moisture content. Modulating the water feed, dry-material flow-rate or a combination of
both may be used to achieve this.
A Hydro-Skid sensor is used to monitor the output of the continuous mixer on a conveyor
belt. In some cases, it may be convenient to use a Hydro-mix sensor at the output of the
mixer, depending on mechanical arrangements.
As with many control systems of this type, there is a time lag between the control action
point - the input to the mixer - and the point at which the measurement can be made.
Hence the response time of the Hydro-View (in terms of the number of samples
parameter) should be set in accordance with the time constant of the system to prevent
unnecessary and erratic modulation of the valve controller.
Systems such as this have been used successfully in the tempering of materials such as
clay and PFA.
Recommendations for best performance
ALWAYS site the moisture sensor in the most appropriate place for the application -
preferably as near to the control point as possible (to minimise time lag) without
compromising the homogeneity of the material passing the sensor. The position chosen
should ensure that the sensor is covered by sufficient material at all times during
measurement and is not in an area prone to build up of waste material, which would lead
to erroneous readings. General advice on this can be found in the Hydronix moisture
sensor data sheets and by contacting your Hydronix supplier.
ALWAYS ensure that the sampling and filter parameters are set appropriately for the
application - guidelines are given in Suggested working values (p40).
ALWAYS provide some means of detecting an empty belt condition when using the Hydro-
Skid sensor. In many cases, simply setting the sensor maximum voltage parameter to a
suitable value will suffice. The purpose of this would be to prevent the control loop adding
water to apparently very dry material. The alarm output relay of the Hydro-View might be
used to signal the controller in this event.
NEVER try to use the Hydro-Skid on very thin layers of material as this will give erroneous
readings. All Hydronix sensors work best in bulk materials.
•Figure 3 - Continuous mixing process

20 HYDRO-VIEW USER GUIDE D0022 REV 1.06
Notes