Foxcroft FX-300-F User manual

0
Please Read Carefully and Save.
The FX-300 analyzer includes an instruction manual that contains important information a out
its operation. Purchasers who install this product for use y others must leave this instruction manual
or a copy with the user.
Document No. MANFX300FDW 2020
Every effort has een made to ensure the accuracy of this document at the time of printing. In accordance
with the company’s policy of continuous product improvement, Foxcroft reserves the right to make product
changes without notice. No lia ility is accepted for any consequential losses, injury or damage resulting from the
use of this document or from any omissions or errors herein.
Foxcroft Equipment & Service Co. Inc.
Model FX-300-F
Drinking Water Ion Selective Electrode
Fluoride Analyzer Instruction Manual

Page Intentionally Left Blank

Ta le of Contents
Section 1 Theory of Operation 1
Section 2 Introduction
2.0 Fluoride Ion Selective Electrodes 2
2.1 HF Ionization Chart 3
2.2 FX-300 Transmitter Navigation and Operation 4
2.3 FX-300-ISE Module Function and Programming List of Parameters 5
2.4 FX-300-ISE Module Description 7
2.41 Sensor Input 7
2.42 Analog Output 7
2.43 Factory Reset 7
2.44 RS485 Mod us 7
2.45 Default Ion Settings 9
2.46 Transmitter Specifications 10
3.0 Installation General Information Power Requirements 10
3.1 Power Requirements, Component Identification 11
3.1 Power Entry Module, Input Output Terminals 12
3.2 Default Wiring Sensor to the Measurement Module 13
3.3 Wiring the 4-20 mA Output 14
3.4 Wiring the 0/4-20 mA Output & FX300-REL Alarm /Relay Control Module 15
3.5 Wiring schematic adding multiple devices to the 4-20mA output loop 15
3.6 New Sensor Installation, Acclimation Time 16
3.61 Su mersi le Sensor Installation 16
3.72 Installation (Inline Sensor Plum ing) 18
3.73 Installation (FX-300-FP Inline Flow Panel) 19
4.0 Startup Overview 20
4.1 Settings to check for systems with ISE modules only 21
4.2 Settings to check for systems with alarm relay modules 21
4.3 OFL and UFL Error codes 22
5 Cali ration 23
5.0 Cali ration Notes 23
5.1 One-Point Offset Cali ration 25
5.3 Two-Point Slope Cali ration 26
5.4 2-Point Slope Cali ration Procedure 27
5.5 How to prepare a fluoride standard solution 28
6 Sensor Maintenance & Cleaning 31
6.1 Cleaning Procedure for High pH & Drinking Water Applications 31
7 Fluoride Sensor Specifications 32
8 Additional Measurement Modules: FX-300-REL Alarm Relay Control Module 33
9 Repair Service Contact & Repair Service Policy 41

1
The FX-300 series analyzers use ion selective electrodes to directly measure the ion of interest in
water without converting the ion to a gaseous form and without the use of reagents. It provides an
online continuous measurement for daily monitoring, trending and process control in applications
including municipal drinking and waste water, and industrial process water and waste streams.
A complete explanation of ion selective electrode theory and operation is eyond the scope of this
manual. A rief general summary is provided elow only to distinguish the analytical method used
from methods used y other types of instrumentation.
The FX-300 uses an electrochemical potentiometric sensor with a mem rane that is selective to, ut
not exclusive to, the ion of interest. This means that it is possi le for other ion types to permeate the
mem rane and react with the sensor. This presents an interference which is present to some degree
in all ion selective electrodes.
When the ions in the fluid eing measured reach equili rium with the internal ion concentration of the
sensor an electrical potential difference develops across the mem rane etween the solution and the
sensor’s internal reference system. The electrical charge in the sensor is proportional to the ion
concentration in the fluid eing measured. The relationship etween ionic concentration and the
electrode potential is governed y the Nernst equation E = E0 + (2.303RT/ nF) x Log(A).
It’s important to note the FX-300 ion selective sensors provide a measurement of free ion activity
(those ions that are not ound to other ions or molecules), and not the actual total ion concentration.
An ion in solution may exist as a free iron, meaning it is not ound to other ions or molecules, or it
may interact and ind with other ions or molecules in the solution. The activity of an ion relates to the
num er of free ions of interest per unit volume of solution. The concentration of the ion of interest
refers to the TOTAL num er of those ions oth free and ound per unit volume of solution
The FX-300 ion selective measurement does not use a method approved for reporting levels to a
governing agency since the sample is not conditioned with reagents or uffers to produce a result. It
will however provide a status of ion activity in the process stream and indication of actual
concentration y using the 1-point offset cali ration to concentration standards that is determined y
an approved gra sample or la oratory analysis instrument that determines the actual concentration.
The activity of free fluoride ions in solutions is pH and temperature dependent over some pH and
temperature ranges. The extent of ionization (HF) conversion to the measura le (F
-
) ion form is also a
pH and temperature dependent process.
Temperature dependence is descri ed y the Nernst equation. The effect on a measurement in
simple terms means that if the temperature fluctuates or the sensor temperature is not in equili rium
with the solution, the readings will also even if the ion activity remains unchanged.
1 Theory of Operation

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2.0 Fluoride Ion Selective Electrodes
The com ination fluoride sensor includes oth the measuring and reference electrodes with
electrolyte, electronics and a high-impedance PVC organic mem rane system in a sealed plastic
ody. As such there are no replacea le or servicea le items in the sensor. The only service required
is occasional cleaning and cali ration.
The recommended pH range of the general purpose fluoride sensors is 5.5 to 9.5pH on a continuous
asis for optimum sensor lifetime. We recommend a pH less than 9.5 to minimize aging on the
crystal. Sensors will start to have some loss of linearity at pH 10. Solutions at pH 11 will destroy
the fluoride crystal.
It is not recommended to operate the general purpose drinking water sensors below 5.5 pH. If
the fl uoride sensor must operate below 5.5 pH you must contact the factory for assistance in
selecting a different sensor or sample point for your application.
At pH levels elow 5.5, the fluoride sensor will not detect the total fluoride content, as some of the
fluoride ion will e converted into the form of dissolved HF gas. To convert the measured fluoride ion
activity (free fluoride) into a total fluoride reading the free fluoride measurement must e
compensated for the effect of pH using the FX-300-TOT module and a pH sensor with FX-300 pH
measurement module. See the pH dependent extent of ionization curve for HF dissolved gas and
fluoride ions (F) for a graphical representation of this phenomenon.
If you have purchased the FX-300-TOT module, you will e a le to compensate for the pH induced
effects on the extent of ionization to find the “total un ound free fluoride” as defined y the sum of the
free ionized fluoride ion species together with the protonated HF ound form.
Please also note that these pH effects are a temperature dependent phenomenon. The provided
extent of ionization curve is only completely valid for pure two component systems with deionized (DI)
water. Real world water solutions of a much more complex makeup may vary somewhat from these
idealized curves, although the deviation is not expected to e vast for most typical systems.
2 Introduction

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2.1 HF Ionization
2 Introduction

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2.2 FX-300 Transmitter Navigation and Operation
Each module has a 3 digit display and LEDs to indicate operating modes. The module is programmed
y the use of 3 keys located on the front panel.
 ‘Mode’ key is used for navigation. The ‘Mode’ key is used to toggle etween operating
modes and for selecting a mode.
 “ppm/mV” indicates the run mode.
 °C mode displays the temperature.
 “Offset” is the mode for the 1-point offset cali ration
 “Slope” is the mode to modify sensor slope.
 “Setup” mode provides access to program the analyzer.
 “Com” LED is illuminates when the Mod us (if included) is active.
For viewing or changing setup / operating parameters use the Mode key to select SETUP and
use the ‘Up’ and ‘Down’ keys to scroll through the parameters. Select a parameter y pressing the
Mode key.
To make a change you must first unlock the software y selecting parameter P01, then use the ‘Up’ or
‘Down’ keys to toggle the lock to “off”.
NOTE: The raw uncompensated (a.k.a. “a solute”) mV potential of the ISE sensor is displayed y
pressing the “Down” key in the main ppm display mode. The display now changes from ppm to
a solute mV units. Negative values will e displayed flashing. The temperature can e cali rated
pushing the “Up” or “Down” uttons when in the temperature display (°C) mode.
2 Introduction

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2.3 FX 300 ISE Module Function and Programming List of Parameters
If the software lock (parameter. no.1) is “on” the parameter can only be read. Set software lock
P01 to “off” to change values.
Par. no.2 sets the module’s address for Mod us communication.
Par. no.3 indicates the type of sensor for the temperature input.
Par. no.4 If Par no.7 is set to ISE, the signal is temperature compensated. Par. no.4 sets
the temperature compensation to either set (manual) or ased on the
measured temperature.
Par. no.5 sets the temperature for when temperature compensation of the pH is in fixed (manual)
mode.
Par. no.6 If a long ca le is used for the Pt100 sensor the ca le impedance should e entered
and compensated for this offset.
Par. no.7 selects the output to e either ISE or temperature.
Par. no.8 sets the analog output to either 0-20mA or 4-20mA.
Par. no.9 sets the analog output scaling to either low (0.00-9.99ppm), mid (00.0-99.9ppm) or
high (000-999ppm) range.
Par. no.10 are used to set the ppm value that corresponds to 0/4mA output setpoint
and no.11 (Par. no.10) and sets the ppm value that corresponds to 20mA output setpoint (Par
no.11). The difference etween Par. no.10 and 11 must e at least 20% of the working
output range selected (either low, mid or hgh range). The display and output ranges
are altogether decoupled.
Par no.12 Varia le to define the mV change for each “Up” or “Down” utton depression when
cali ration is performed.
Par. no.13 Displays formula weight of measured ion (next page details how to determine which ion
correspond to this value)
Par. no.14 View and edit the working (effective) sensor offset
Par. no.15 View and edit the working (effective) sensor slope
Par. no.16 Offset adjustment for low 0/4mA analog output trim.
Par. no.17 Gain adjustment for 20mA high analog output trim.
Par. no.18 If no keys are pressed for 10 min the display will show flashing ar (Energy Save).Press
any key to return.
Par. no.19 The Mod us standard requires a audrate of 9,600 or 19,200 set in accordance with
the Mod us-master.
Par no.20 Feature to reset the analyzer ack to factory default.
NOTE: To exit setup mode, press the ‘down’ button until parameter P00 is displayed, then press
‘mode’ until PPM (run) mode indicator lights
2 Introduction

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2.3 FX 300 ISE Module Function and Programming List of Parameters
No Parameter Description Range Default
1 Lock Software lock On / Off On
2 Address Address on Mod us Off, 1...247 Off
3 Temperature Type of input Pt100, Pt1000 Pt1000
4 Compensation Temp. Comp. of pH Auto, Set (Manual) Auto
5 Comp. Temp. Compensating temperature 0..150 25
6 Ca le impedence Impedance of Pt100 ca le 0.0 .. 9.9Ω 0.0
7 Output varia le ISE or temperature ISE, °C ISE
8 Analog output range ISE output range 0-20, 4-20 4-20
9 ISE ppm output range Low (0-10.0), mid (0-100)
and high (0-999)
10.0, 100, 999 10.0
10 0/4mA Set Low ppm setpoint 0.00 .. 999 0.00
11 20mA set High ppm setpoint 0.00 .. 999 10.0
12 Step change mV increment per ‘Up’ or ‘Down’
utton depression
0=0.02, 1=0.05,
2=0.10, 3=0.20,
4=0.50, 5=1.0,
6=2.0
2 (0.10mV)
13 View formula weight of ion Grams per mol of ion XX.XX per ion
weight
19 (F
-
only)
14 View current sensor offset mV at iso-concentration Per ISE sensor -47 (F
-
)
a
15 View current sensor slope mV per decade response Per ISE sensor -57.2 (F
-
) a
16 0/4mA offset Trim low +/-9.99% 0.00
17 20mA gain Trim high +/-9.99% 0.00
18 Energy save Energy save On/ Off On
19 Baudrate Mod us 9,600/19,200 19,200
20 Back to default Reset to default Def = reset
Par = no reset
Par
a On the display this value will e flashing, which indicates a negative value.
2 Introduction

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2.4 FX-300-ISE Module Description
2.41 Sensor Input
The sensor without preamplifier is connected directly to the FX300-pH/ORP/ISE module. The mV
signal from the sensor is processed y an integrated high impedance amplifier. The FX300-
pH/ORP-X hardware version can support internal or external preamplifiers to ena le installations
that require long ca le lengths or to operate in high interference areas. Temperature measurement
with a Pt100/Pt1000 element in the sensor allows automatic temperature compensation to e
performed.
2.42 Analog Output
The FX300 transmitters have a single scala le analog output of either 0-20 or 4-20 mA (selecta le).
The difference required etween the minimum (0/4mA) and maximum (20mA) output is 20% of the
selected range (low 0-10, mid 0-100 or high 0-1000 ppm). For example, if the low range (0-10) is
selected then the output could e as narrow as 0-2 ppm for the 0/4-20 mA scaling. The output is
proportional to ISE ppm or temperature and is galvanically insulated from the input.
2.43 Factory Reset
You can use parameter (P20) on the FX-300-ISE transmitter to reset the unit ack to the factory
dispatched configuration. If you perform a factory reset you will need to re-scale the current output
and and re-configure alarm settings and limits. You will also need to repeat your 2-point cali ration
using cali ration solutions that are one decade (lOX) apart in value. In addition, you will need to once
again place the ISE sensor ack into service and allow it to reach equili rium. You will then also need
to repeat your 1-point gra sample offset cali ration.
2.44 RS485 Modbus (Optional)
RS485 Mod us output is availa le in two ways.
1. It can e integrated into the pH or ISE module at time of order only.
2. It is also availa le in the FX-300-TOT module, which can e added at any time.
Acquired data is transferred using Mod us standard for multi-drop communication and is connected
using RS485. The Mod us-master may e the FX300-DAT data logger module or any SCADA
system. When units are ordered with Mod us option, the free of charge Windows data logging and
graphing software and e used to monitor and record all process and temperature values from up
to 247 transmitter simultaneously at distances up to 6500 feet (2 kilometers).
In order to utilize the Mod us interface the FX-300-ISE must e ordered with Mod us. FX-300-ISE
may e used as a slave for the ‘Dat’ - unit FX-300-DAT or as a slave in a SCADA system. The setup /
communication for each case will e explained in the following.
Mod us With FX-300-DAT
If FX-300-ISE is used together with the FX-300-DAT data logger, the user must pay attention to two
things: The aud rate on the Mod us as well as the address of the FX-300-ISE. The aud rate
(P14) must e set to the aud rate of the FX-300-DAT. Whether a aud rate of 19,200 or 9,600 is
used is of no importance, as long as all units on the Mod us are set to the same aud rate.
2 Introduction