TPS MicroChem-Sal User manual

MicroChem-Sal_TDS
MicroCHEM-Sal Transmitter Module
Date:23-Nov-2006
Version: 1.02
Author: AB
TPS Pty Ltd
ABN 30 009 773 371
Phone: [phone]
International: 61 7 32058027
Email: [email protected]
Web: www.tps.com.au

Congratulations !
Your new microCHEM-Sal transmitter module is a simple, lower power device
for interfacing a Salinity/TDS sensor with datalogging and process control
equipment. The industry standard 0 to 1 V DC and 0 to 5 V DC outputs ensure
that the microCHEM-Sal is compatible with most such devices.
The microCHEM-Sal is a breeze to operate. This manual has been designed to
help you get started, and also contains some handy application tips. If at any
stage you require assistance, please contact either your local TPS representative
or the TPS factory in Brisbane.
The manual is divided into the following sections:
1. Table of Contents
Each major section of the handbook is clearly listed. Sub-sections have also
been included to enable you to find the information you need at a glance.
1. Introduction
The introduction has a diagram and explanation of the display and controls
of the microCHEM-Sal. It also contains a full listing of all of the items that
you should have received with the unit. Please take the time to read this
section, as it explains some of items that are mentioned in subsequent
sections.
1. Main Section
The main section of the handbook provides complete details of the
microCHEM-Sal, including operating modes, calibration, troubleshooting,
specifications, and warranty terms.
1. Appendices
Appendices containing background information and application notes are
provided at the back of this manual.
2

Contents
1. Introduction 4
1.1 Unpacking Information 4
1.2 Specifications 5
2. Installation and Set-up 6
2.1 Connection and Configuration Diagram 6
2.2 Mounting the Enclosure 7
2.3 Mounting the Sensors 7
2.4 Terminal Connections 8
2.5 Selecting 0 to 1 V DC or 0 to 5 V DC Output 8
3. Calibration 9
3.1 Calibration Procedure 9
3.2 Calibration Notes 11
3.3 Calibration Data 11
4. Troubleshooting 12
4.1 Instrument Function Troubleshooting 12
4.2 Salinity/TDS Troubleshooting 12
5. Warranty 15
6. Appendices 18
6.1 Re-setting the Measurement Range 18
6.2 Care, Cleaning and Maintenance of Salinity/TDS Electrodes 19
3

1. Introduction
1.1 Unpacking Information
Before using your new microCHEM-Sal, please check that the following
accessories have been included:
Part No
1. microCHEM-Sal Transmitter Module 112146
1. Mounting feet, kit of 4, complete with screwsNRMICRO
1. microCHEM-Sal Handbook 130050
2. Salinity/TDS standard to suit specified range, 200mL
Salinity/TDS Sensors…
1. k=0.1 GK Series Salinity/TDS Sensor, 5m 112205
2. k=1.0 GK Series Salinity/TDS Sensor, 5m 112206
3. k=10 GK Series Salinity/TDS Sensor, 5m 112207
4

1.2 Specifications
Ranges
k=0.1 Sensor 0 to 10.00 ppM, 0 to 100.0 ppM, 0 to 1000 ppM
k=1.0 Sensor 0 to 100.0 ppM, 0 to 1000 ppM, 0 to 10.00 ppK
k=10 Sensor 0 to 1000 ppM, 0 to 10.00 ppK, 0 to 100.0 ppK
Resolution ±1mV (0 – 1 V DC Output) or ±5mV ( 0 – 5 V DC Output)
Accuracy ±1mV (0 – 1 V DC Output) or ±5mV ( 0 – 5 V DC Output)
Linearity ±1mV (0 – 1 V DC Output) or ±5mV ( 0 – 5 V DC Output)
Repeatability ±1mV (0 – 1 V DC Output) or ±5mV ( 0 – 5 V DC Output)
Ambient Drift <0.02% / OC
Long term drift <0.1% per year
Zero Range ±5 %
Span Range 70 to 130%
Temperature Compensation Automatic, 0 to 100.0 OC
Enclosure Polycarbonate, waterproof to IP65
Analogue Outputs 0 to 1 V DC
or 0 to 5 V DC
Isolation Galvanic isolation of sensor input
Power 12V DC, approx 10mA
Dimensions Enclosure : 125 x 85 x 56 mm
PCB only : 115 x 77 mm
(82 x 58 mm mounting hole
centres)
Mass Instrument only : Approx 250 g
Full Kit : Approx 1.0 kg
Operating Environment:Temperature : 0 to 45 oC
Humidity : 0 to 95 % R.H.
5

2. Installation and Set-up
2.1 Connection and Configuration Diagram
The diagram below is provided as a reference for the terminal connections,
configuration jumpers and user-adjustable trimmers that are discussed throughout
this section.
6

2.2 Mounting the Enclosure
The microCHEM-Sal can be mounted directly onto a wall or into a separate
enclosure using the mounting kit supplied. Please use the screws supplied to
ensure that the waterproof integrity of the enclosure is not compromised.
2.3 Mounting the Sensors
Mounting the sensor is a very important aspect of the installation, and is often
done incorrectly. In automatic control situations, the sensor should always be
mounted as close as possible to the injection point. This will cause the sensor to
detect the added chemicals or water immediately, and shut the addition off until
mixing has taken place. For in-line mounting, it is important that injection is
upstream. Additionally, the line must be run through a mixing chamber, such as a
large drum, to ensure that the injected chemical or water has mixed in properly
by the time the solution flows past the sensor. There must always be adequate
flow of fresh sample past the sensor for accurate monitoring. The diagrams below
show typical mounting arrangements for “dip” mounting and in-line mounting.
Dip Mounting In-line Mounting
1. Injection point close to sensor. 1. Injection point upstream from
2. Continuous stirring. and close to sensor.
2. Mixing container after injection
and before sensor.
3. A flow-through assembly for in-line
mounting is available from TPS.
7

2.4 Terminal Connections
Terminal No.
Connection
Colour
Sensor Connections
1
Salinity/TDS Sensor ATC
Blue
2
Salinity/TDS Sensor ATC
White
3
No Connection
4
Shield (if fitted to cable)
Green or Braid
5
Salinity/TDS Sensor Cell
Red
6
Salinity/TDS Sensor Cell
Black
Power Input Connections
–
Negative of 12V DC Input
Customer-defined
+
Positive of 12V DC Input
Customer-defined
Signal Output Connections
COM
Common of voltage output
Customer-defined
OUT
Positive of voltage output
Customer-defined
2.5 Selecting 0 to 1 V DC or 0 to 5 V DC Output
1. Locate the jumper labelled J1 on the main circuit board.
2. Set J1 to closed to select 0 to 1 V DC output.
3. Set J1 to open to select 0 to 5 V DC output.
Note
When setting J1 to open, we recommend that it is fitted to one of the pins.
This is a safe place to keep it, in case the microCHEM-Sal needs to be reset for
0 to 1 V DC output in the future.
8

3. Calibration
3.1 Calibration Procedure
1. Switch the microCHEM-Sal on.
1. Ensure that the Salinity/TDS sensor is correctly connected (see section 2.4).
2. For the GK-1 sensor (part no 112206), ensure that the white protective cover
is fitted with the vent hole towards the cable end of the sensor.
3. Rinse the Salinity/TDS sensor in distilled water and blot dry.
Zero Calibration
4. Shake the Salinity/TDS sensor dry and hang it in air. DO NOT wipe the
platinised platinum electrode surface, as this will remove the platinum-black
layer.
5. When the reading has stabilised, adjust the ZERO control until the output is
exactly 0 mV.
Span Calibration
6. Place the Salinity/TDS sensor into a small sample of Salinity/TDS standard.
A suitable standard should be chosen for the display range of the unit.
9. For GK-1 (part no 112206) and GK-10 (part no 112207) sensors, ensure that
they are immersed at least to the vent hole in the white plastic cover. The
GK-0.1 (part no 112205) sensor does not have a cover, so it should be
immersed to the large thread (see diagrams below).
9

10. When the reading has stabilised, adjust the SPAN control until the output
corresponds to the value shown in the Calibration Data table in section 3.3.
10

11. Rinse the Salinity/TDS sensor in distilled water and blot dry.
12. The microCHEM-Sal is now calibrated and ready for Salinity/TDS
measurements.
3.2 Calibration Notes
1. The Zero calibration is quite stable long term, and only needs to be performed
monthly as a routine check. In applications where the sensor can become dirty
or coated with oils etc., a Zero calibration may need to be done weekly.
1. A Span calibration should be performed at least weekly. Of course, more
frequent calibration will result in greater confidence in results.
3.3 Calibration Data
The following table details the output for Salinity/TDS standards available from
TPS to suit the ranges of the microCHEM-Sal. Other Salinity/TDS standards
may be used, in which case you will need to calculate the output of your
microCHEM-Sal for the standard being used.
Range
Standard
Output
0 to 1 V
Output
0 to 5 V
0 to 10 ppM
No standard available for this
range.
0 to 100 ppM
69.5 ppM
695 mV
3475 mV
0 to 1000 ppM
900 ppM
900 mV
4500 mV
0 to 10 ppK
8.00 ppK
800 mV
4000 mV
0 to 100 ppK
36.0 ppK
360 mV
1800 mV
11

4. Troubleshooting
4.1 Instrument Function Troubleshooting
Symptom
Possible Causes
Remedy
Incorrect analogue
output signal.
1. J1 Output Jumper
incorrectly set for required
output.
1. Instrument is faulty.
Check that the J1 Output
Jumper is correctly set for 0 to
1 V DC or 0 to 5 V DC output,
as per requirements. Adjust if
necessary (see section 2.5).
Return to TPS for repair.
4.2 Salinity/TDS Troubleshooting
Symptom
Possible Causes
Remedy
Zero calibration
fails (insufficient
range with ZERO
control).
1. Electrode has Zero error.
1. Sensor is faulty.
Thoroughly rinse electrode in
distilled water and allow to
completely dry in air before
attempting zero calibration.
If instrument does not calibrate
at Zero with electrode
disconnected, then the
instrument is faulty.
Replace sensor.
Standard calibration
fails, reading is too
low and cannot be
adjusted high
enough.
1. Electrode is not immersed
deeply enough.
1. Electrode may have a
build-up of dirt or oily
material on electrode wires.
2. Platinum-black coating has
worn off.
3. Standard solution is
inaccurate.
4. Electrode is faulty.
Immerse electrode at least to
the vent hole in the white
plastic cover.
Clean electrode, as per the
instructions detailed in section
6.2.2.
Electrode requires
replatinisation.
Return to the factory, or see
details in section 6.2.3.
Replace standard solution.
Return electrode to factory for
repair or replacement.
Continued next page…
12

13

Salinity/TDS Troubleshooting, continued…
Standard calibration
fails, reading is too
high and cannot be
adjusted low
enough.
1. White protective cover is
not fitted (GK-1 sensor).
1. Standard solution is
inaccurate.
2. Electrode may have a
build-up of conductive
material, such as salt.
3. Electrode is faulty.
The white protective cover
MUST be fitted for correct
readings for GK-1 sensor.
Replace standard solution.
Clean electrode, as per the
instructions detailed in section
6.2.2.
Return electrode to factory for
repair or replacement.
Inaccurate readings,
even when
calibration is
successful.
1. Electrode may have a
build-up of dirt or oily
material on electrode wires.
1. Platinum-black coating has
worn off.
Clean electrode, as per the
instructions detailed in section
6.2.2.
Electrode requires
replatinisation.
Return to the factory, or see
details in section 6.2.3.
Readings drift.
1. Electrode may have a
build-up of dirt or oily
material on electrode wires.
Clean electrode, as per the
instructions detailed in section
6.2.2.
Readings are low or
near zero.
1. Electrode may have a
build-up of dirt or oily
material on electrode wires.
1. Electrode is not immersed
deeply enough.
2. Electrode is faulty.
Clean electrode, as per the
instructions detailed in section
6.2.2.
Immerse electrode at least to
the vent hole in the white
plastic cover.
Return electrode to factory for
repair or replacement.
14

5. Warranty
TPS Pty. Ltd. guarantees all instruments and electrodes to be free from defects in
material and workmanship when subjected to normal use and service. This
guarantee is expressly limited to the servicing and/or adjustment of an instrument
returned to the Factory, or Authorised Service Station, freight prepaid, within
twelve (12) months from the date of delivery, and to the repairing, replacing, or
adjusting of parts which upon inspection are found to be defective. Warranty
period on electrodes is three (3) months.
There are no express or implied warranties which extend beyond the face hereof,
and TPS Pty. Ltd. is not liable for any incidental or consequential damages
arising from the use or misuse of this equipment, or from interpretation of
information derived from the equipment.
Shipping damage is not covered by this warranty.
PLEASE NOTE:
A guarantee card is packed with the instrument or electrode. This card must be
completed at the time of purchase and the registration section returned to TPS
Pty. Ltd. within 7 days. No claims will be recognised without the original
guarantee card or other proof of purchase. This warranty becomes invalid if
modifications or repairs are attempted by unauthorised persons, or the serial
number is missing.
PROCEDURE FOR SERVICE
If you feel that this equipment is in need of repair, please re-read the manual.
Sometimes, instruments are received for "repair" in perfect working order. This
can occur where batteries simply require replacement or re-charging, or where
the electrode simply requires cleaning or replacement.
TPS Pty. Ltd. has a fine reputation for prompt and efficient service. In just a few
days, our factory service engineers and technicians will examine and repair your
equipment to your full satisfaction.
TO OBTAIN THIS SERVICE, PLEASE FOLLOW THIS PROCEDURE:
Return the instrument AND ALL SENSORS to TPS freight pre-paid and insured
in its original packing or suitable equivalent. INSIST on a proof of delivery
receipt from the carrier for your protection in the case of shipping claims for
15

transit loss or damage. It is your responsibility as the sender to ensure that TPS
receives the unit.
16

Please check that the following is enclosed with your equipment (our service
form is available on our website www.tps.com.au):
Your Name and daytime phone number.
Your company name, ORDER number, and return street address.
A description of the fault. (Please be SPECIFIC.)
(Note: "Please Repair" does NOT describe a fault.)
Your equipment will be repaired and returned to you by air express where
possible.
For out-of-warranty units, a repair cost will be calculated from parts and labor
costs. If payment is not received for the additional charges within 30 days, or if
you decline to have the equipment repaired, the complete unit will be returned to
you freight paid, not repaired. For full-account customers, the repair charges will
be debited to your account.
Always describe the fault in writing.
Always return the sensors with the meter.
17

6. Appendices
6.1 Re-setting the Measurement Range
The range of the microCHEM-Sal may be re-set using the table of jumper
settings shown below. Refer to the diagram in section 2.1 for the location of the
Aand Brange jumper blocks. Attach spare jumpers off single unused pins for
safe storage.
Sensor k Factor
Range
k=0.1
k=1.0
k=10
0 to 10 ppM
This range not
available for
k=1.0 sensor.
This range not
available for
k=10 sensor.
0 to 100 ppM
This range not
available for
k=10 sensor.
0 to 1000 ppM
0 to 10 ppK
This range not
available for
k=0.1 sensor.
0 to 100 ppK
This range not
available for
k=0.1 sensor.
This range not
available for
k=1.0 sensor.
18

6.2 Care, Cleaning and Maintenance of Salinity/TDS
Electrodes
6.2.1 Care of Salinity/TDS electrodes
The Salinity/TDS section of the electrode supplied with your microCHEM-Sal
consists of two platinum wires that are plated with a layer of “platinum-black”.
This is quite a soft layer and is required for stable, accurate measurements. In
time, the platinum-black layer may wear off in some applications, at which time
the electrode will require replatinising (see section 6.2.3). You can help to
maintain the platinum-black layer by following these simple rules:
1. NEVER touch or rub the electrode wires with your fingers, cloth etc.
1. Avoid using the electrode in solutions that contain a high concentration of
suspended solids, such as sand or soil, which can abrade the electrode wires.
Filter these types of solutions first, if possible.
2. Avoid concentrated acids. If you must measure acids, remove the electrode
immediately after taking the measurement and rinse well with distilled water.
Salinity/TDS electrodes can be stored dry. Ensure that the electrode is stored in a
covered container, to avoid dust and dirt build-up.
6.2.2 Cleaning Salinity/TDS of Electrodes
Platinised platinum Salinity/TDS electrodes can only be cleaned by rinsing in a
suitable solvent. DO NOT wipe the electrode wires, as this will remove the
platinum-black layer.
1. Rinsing in distilled water will remove most build-ups of material on the
electrode wires.
1. Films of oils or fats on the electrode wires can usually be removed by rinsing
the electrode in methylated spirits.
2. Stubborn contamination can be removed by soaking the electrode in a solution
of 1 part Concentrated HCl and 10 parts distilled water. The electrode should
not be soaked for more than approximately 5 minutes, otherwise the
platinum-black layer may start to dissolve.
3. If all of these methods fail, then the last resort is to physically scrub the
electrode wires, which will remove the contaminant and the layer of
platinum-black. Use only a cloth or nylon scouring pad. DO NOT USE
STEEL WOOL. The electrode will then need to be cleaned in HCl, as per step
3 and replatinised, as per section 6.2.3.
19

6.2.3 Replatinising Salinity/TDS Electrodes
There are several ways to replatinise Salinity/TDS electrodes.
1. The simplest way is to return the electrode to the TPS factory. We can fully
clean the electrode, replatinise it and test all aspects of its performance.
1. An automatic replatiniser is available from TPS, along with replatinising
solution. This will plate the electrodes for the right amount of time at the
correct current. Ordering details are as follows:
Automatic Salinity/TDS Electrode Replatiniser Part No 122160
20mL Platinising Solution (suitable for approx 30 uses) Part No 122300
2. Salinity/TDS electrodes can be manually replatinised, according to the
following procedure:
1) Soak the electrode in a solution of 1 part Concentrated HCl and 10 parts
distilled water for approximately 5 minutes.
2) Rinse the electrode well in distilled water.
3) Immerse the electrode in platinising solution to the same level as for
calibration (see section 3.1). Platinising solution is available from TPS
(part no 122300). Alternatively, platinising solution can be prepared by
dissolving 1g of Hydrogen Chloroplatinate (H2PtCl16) in 30mL of distilled
water, and including about 0.01g of Lead Acetate ((CH3COO)2Pb) and a
drop or two of concentrated HCl.
4) Apply a direct current of 10mA between red and black wires of the
electrode cable, as per the diagram below. Reverse the polarity every 30
seconds. After approximately 8 minutes (4 minutes per electrode wire),
they should have an even “soot” like appearance. Avoid excess current and
this will cause incorrect platinising.
5) After platinising, rinse the electrode well in distilled water.
6) If you have any doubts about any of these steps, then you should consider
returning the electrode to the factory. The cost of replatinising is quite low,
and you will be guaranteed of the best possible result.
20