ISCO 4230 User manual

4230 Bubbler
Flow Meter
The 4230 Bubbler Flow Meter Pocket Guide
is provided as a handy field reference. It is
not intended to replace the instruction
manual, but complements it by providing
condensed instructions. Study the manual
thoroughly before installing or operating the
flow meter.
COPYRIGHT © 1994 by
Teledyne Isco, Inc., 4700 Superior St.,
Lincoln, Nebraska, U.S.A. 68504
Phone: [phone]
Toll Free: [phone]
FAX: [phone]
www.isco.com
Part #60-3233-102
Revision H, May 11, 2006

WARNING
The installation and use of this product may
require you to work in locations where you
could be seriously injured or even killed. Take
whatever precautions are necessary to ensure
your safety before entering the installation.
Never work alone or unsupervised. Install and
operate this product in accordance with all
applicable safety and health regulations, as
well as any appropriate local ordinances.
This product is often installed in confined
spaces. Examples of confined spaces are
manholes, pipelines, digesters, and storage
tanks. These places can be dangerous or fatal
if you are not suitably prepared. The primary
hazards are the presence of poisoned air, the
lack of ventilation, and the possibility of falls.
Other hazards may be present, as well. Work
in such places is governed by OSHA
1910.146, and may require a permit before
entering.
Material Safety Data Sheets (MSDS) for
chemical agents supplied or recommended for
use with this product are in the MSDS
Appendix in the back of the instruction
manual. These sheets provide information
about possible hazards from the chemicals.
Additional MSDS, covering various
proprietary agents (name-branded or
trademarked mixtures) that can also be used
with this product, are available from the
manufacturers of those agents.

Table of Contents
iii
Table of Contents
1.
Getting Started
1.1 Becoming Familiar with the 4230 Flow
Meter . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1.1 Selection of a Power Source . . 1-2
1.1.2 Turning the Flow Meter On . . 1-3
1.1.3 Adjusting the Bubble Rate . . . 1-3
1.2 Checking the Installation . . . . . . . . . 1-4
1.2.1 Bubble Lines in High-Velocity
Streams . . . . . . . . . . . . . . . . . . 1-6
1.2.2 Clogging Bubble Lines . . . . . . 1-7
1.3 Options and Capabilities . . . . . . . . . . 1-8
1.3.1 Flow Metering Inserts . . . . . . 1-8
1.3.2 Connection to a Sampler . . . . 1-9
1.3.3 Adjusting Level . . . . . . . . . . . . 1-9
1.3.4 Data Acquisition and Storage
(Flowlink®) . . . . . . . . . . . . . . 1-10
1.3.5 Parameter Sensing with the 4230
Flow Meter . . . . . . . . . . . . . . 1-12
2.
Programming Introduction
2.1 Why Programming Is Necessary . . . . 2-1
2.1.1 Operation of the Keypad and
Display . . . . . . . . . . . . . . . . . . 2-2
2.2 Keypad Functions . . . . . . . . . . . . . . . 2-4
2.3 Programming Procedure . . . . . . . . . . 2-7
2.4 Description of Program Steps . . . . . 2-10
2.4.1 Step 1 - Operating Mode . . . 2-10
2.4.2 Step 2 - Flow Conversion Type . .
2-11
2.4.3 Step 3 - Adjust Level, Parameters
2-15

iv
2.4.4 Step 4 - Reset Totalizer . . . . 2-17
2.4.5 Step 5 - Sampler Pacing . . . . 2-17
2.4.6 Step 6 - Sampler Enable . . . . 2-19
2.4.7 Step 7 - Alarm Dialout Mode 2-20
2.4.8 Step 8 - Printer . . . . . . . . . . . 2-21
2.4.9 Step 9 - Reports/History . . . . 2-22
2.5 Interpreting the Program Screens . 2-22
3.
Programming
3.1 Step 1 - Operating Mode . . . . . . . . . . 3-1
3.2 Step 2 - Flow Conversion . . . . . . . . . 3-36
3.2.1 Flow Metering Inserts . . . . . 3-45
3.2.2 Enter Maximum Head - All
Models . . . . . . . . . . . . . . . . . . 3-46
3.2.3 Programming the 4-20 mA
Outputs . . . . . . . . . . . . . . . . . 3-46
3.3 Step 3 - Port to Adjust . . . . . . . . . . . 3-48
3.4 Step 4 - Reset Totalizer . . . . . . . . . . 3-55
3.5 Step 5 - Sampler Pacing . . . . . . . . . 3-56
3.6 Step 6 - Sampler Enable . . . . . . . . . 3-61
3.7 Step 7 - Alarm Dialout Mode . . . . . . 3-67
3.8 Step 8 - Printer . . . . . . . . . . . . . . . . . 3-71
3.9 Step 9 - Reports/History . . . . . . . . . 3-75
4.
Maintenance
4.1 Care of the Flow Meter Case . . . . . . . 4-1
4.1.1 Care of the Case Seal . . . . . . . 4-2
4.1.2 Preventing Moisture Damage 4-2
4.2 Changing the Printer Paper and Ribbon
4-3
4.2.1 Installing the New Roll of Paper .
4-4
4.2.2 Ink Ribbon Replacement . . . . 4-6
4.3 Maintenance of the Bubble Line . . . . 4-7
4.3.1 Automatic Air Purge . . . . . . . 4-8
4.4 Maintenance of the Batteries . . . . . . 4-8
4.4.1 Charging the Nickel-Cadmium

Table of Contents
v
Battery . . . . . . . . . . . . . . . . . . 4-9
4.4.2 Five Station Battery Charger 4-9
4.4.3 Self-Discharge Characteristic . . .
4-10
4.4.4 Hazards of Overcharging . . . 4-11
4.4.5 Charging from Another Source . .
4-11
4.4.6 Memory Effects Temporary . 4-12
4.4.7 Internal Fuse . . . . . . . . . . . . 4-12
4.4.8 Using the Lead-Acid Battery 4-13
4.4.9 Using Other Types of Batteries . .
4-14
4.4.10 Attaching the Battery . . . . . 4-15
4.5 Regenerating the Desiccators . . . . . 4-16
4.5.1 Regenerating the Internal Case
Desiccant . . . . . . . . . . . . . . . . 4-16
4.5.2 Regenerating the External
Desiccant Cartridges . . . . . . 4-18

vi

1-1
4230 Bubbler
Flow Meter
Section 1
Getting Started
1.1 Becoming Familiar with the
4230 Flow Meter
The 4230 Flow Meter is a
microprocessor-equipped flow meter capable of
measuring flow rate in a wide variety of open
channels. The 4230 Flow Meter uses the
bubbler method for sensing level. A small air
pump and reservoir provide a source of
pressurized air. A transducer inside the flow
meter senses the air pressure necessary to force
a bubble from the end of a tube submerged in
the flow stream. As the liquid level increases,
the pressure required to release the bubble also
increases.
The flow meter converts the output from the
pressure transducer to a level reading. Built-in
level-to-flow rate tables convert the level to flow
rate. The level and flow rate appear on a
two-line, eighty character liquid crystal display
(LCD). These flow meters are equipped with an
internal printer to provide a continuous printed
record of level, flow rate, and other information

4230 Bubbler Flow Meter
1-2
that may be used for later reference. The Flow
Meters also have memory allocated that you
can set up to store level and other readings. You
must use Flowlink®, Teledyne Isco’s
proprietary data processing and acquisition
software to initialize (set up) and access this
memory.
1.1.1 Selection of a Power Source
Teledyne Isco offers a variety of power sources
to operate the flow meter. For
commercially-powered installations, there is
the AC Power Supply. Also available is a power
supply with a 1.2 Ah (Ampere-hour) standby
battery built in, the Battery-Backed Power
Supply. For applications where there is no AC
power connection available, Teledyne Isco offers
a 4 Ah nickel-cadmium battery
(Nickel-Cadmium Battery), or a 6 Ah
gelled-electrolyte battery (Lead-Acid Battery).
All these power sources mount on top of the
flow meter and are secured with rubber draw
catches. The cable with the two-pin connector
(12 volt) attaches to the +12 VDC connector on
the flow meter.
Battery life expectancy varies from about seven
to fourteen days between recharge cycles,
depending on the settings for the bubble rate
and the setting for the printer chart speed. For
very remote sites where changing the battery is
difficult, Teledyne Isco offers the Solar Panel
Battery Charger, used with the Lead-Acid
Battery. You may also power the 4230 Flow

Section 1 Getting Started
1-3
Meter with a deep-cycle R-V or marine battery.
You must mount these larger batteries
externally, as they are quite large. Teledyne
Isco offers a special connect cable for them.
1.1.2 Turning the Flow Meter On
After you have connected the flow meter to
power, turn the flow meter on with the ON
button located on the keypad. When the flow
meter is turned on, the air pump will run for
awhile, and then stop when the reservoir tank
is pressurized. If it does not stop, locate the
Bubble Rate Adjust Valve on the side of the
flow meter cabinet and turn it clockwise until it
just seats. Do not over-tighten or force the
valve; the needle-and-seat are fragile and can
easily be broken.
1.1.3 Adjusting the Bubble Rate
Locate the Bubble Rate Adjust valve on the
flow meter’s side. If it is locked, use the small
hex wrench supplied with the flow meter to
release the lock. (Refer to the manual for
details.) Attach a bubble line (identical in
diameter and similar in length to the one that
will be used) to the Bubble Line outlet. Place
the free end of the bubble line in a container
(preferably clear) of water. Set the container
beside the flow meter so you can watch the
bubbles coming out of the end. Adjust the valve
until a bubble rate of one bubble per second is
reached. Lock the valve handle with the hex
wrench supplied with the flow meter.

4230 Bubbler Flow Meter
1-4
Note
Teledyne Isco recommends setting the bubble rate in
the shop first, as this is easier with a small container of
clear water placed beside the flow meter. Using a
different length and diameter bubble line than the
installation will result in an inaccurate setting. In any
case, you should still recheck the bubble rate after
installation, particularly if the bubble line will be under
several feet of water in the flow stream.
1.2 Checking the Installation
At the job site it is worthwhile to check the
installation to see that it was made correctly
and to make sure nothing has changed which
could affect the accuracy of the measurements
made by the flow meter. If the flow meter or
bubble line is installed in a sewer or manhole
please read and observe the following warning:
DANGER
YOU CAN BE KILLED working in sewers or
manholes if you do not follow proper safety
procedures. Besides the risk of falling,
poisonous gases in most sewers can
overcome you quickly, without warning.
Safety information is provided in the 4230
Flow Meter Instruction Manual under the
heading of Safety Considerations. Please
read and follow these procedures; the life
you save may be your own.

Section 1 Getting Started
1-5
If the installation is temporary, make sure the
flow meter is installed so it is not difficult to
reach in case you need to change the
programming or chart paper. The unit should
not be a hazard to anyone entering the
manhole. You can lay the flow meter
horizontally or hang it vertically with a
suspension harness from the ladder. Make sure
the flow meter is suspended well above the
maximum level the flow stream can reach;
water drawn into the desiccator cartridge will
cause serious damage to the unit. If this is not
possible, attach a vinyl line to the open end of
the desiccator cartridge and route the line to a
place well above the maximum expected liquid
level.
If the installation is permanent, check to make
sure that any work going on in the area has not
caused any damage to the wiring or bubble
lines. Check the bubble line where it attaches to
the flow meter to see if flexing has cut the
silicone tubing used to connect the 1/8" bubble
line to the barbed fitting. A crack in the silicone
tubing will appear as a white line across the
middle of the tubing. The resulting leakage will
seriously affect the accuracy of the readings.
Check to make sure the bubble line is secure
from the flow meter to where it enters the flow
stream. Keep the bubble line as short as
possible between the flow meter and the
measuring point in the flow stream. Cut off any
excess length of tubing. Do not coil it up or let it
drift in the stream. Make sure the end of the

4230 Bubbler Flow Meter
1-6
bubble line is installed correctly (at a right
angle to the flow) and securely at the proper
measuring place in the primary device.
This point is usually below the “zero” level of
the primary device and a prescribed distance
upstream from the crest of the device. (This
distance cannot be called out specifically; it
depends on the primary measuring device.)
Refer to the Isco Open Channel Flow
Measurement Handbook for this information.
Flumes can be made with a specific location for
the bubble line. The Adjust Level/Parameters
programming step lets you install the bubble
line anywhere between ten feet above or below
the actual “zero” level of the primary device. In
practice, the installation is usually close to the
“zero” point.
Note
The 4230 Flow Meter cannot measure level below the
bubble line outlet. If you wish to measure accurately
down to the “zero” level of the device, install the bubble
line outlet one to two inches below the “zero” point of
the primary device, and adjust the level appropriately at
the flow meter. This way the liquid level will always be
higher than the bubble line outlet.
1.2.1 Bubble Lines in High-Velocity Streams
If the velocity of the flow stream is more than
five feet per second, and the bubble line outlet
is mounted at a right angle to the flow, the
measured level will tend to be lower than
actual. You can use the Adjust
Level/Parameters step to compensate for this

Section 1 Getting Started
1-7
difference when the level (and velocity) are at a
high point, but a reduction in the flow rate will
result in inaccurate settings. The best way to
overcome this problem is to use a stilling well.
You can also make a depression in the bottom of
the flow stream and place the bubbler there,
but flow streams with significant solids content
may fill the depression and restrict the bubbler.
Or, you can form a 90° bend about two inches
from the end of the bubble line and then place
this bend so it points downstream, parallel with
the flow.
1.2.2 Clogging Bubble Lines
In some flow streams, clogging of the bubble
line from algae, silt, or suspended solids may be
a problem. There are several possible solutions
you can try. You can increase the automatic
purge frequency. This is preferable to
increasing the bubble rate, and is highly
recommended where the flow meter is powered
from AC. Teledyne Isco has stainless steel
bubble line extensions available that may be
helpful, and for situations where algae tends to
grow in the lines, copper tubing is useful. The
copper salts formed over time in the flow
stream are algicidal agents and will inhibit the
growth of algae.

4230 Bubbler Flow Meter
1-8
1.3 Options and Capabilities
1.3.1 Flow Metering Inserts
For temporary monitoring purposes in 6", 8",
10", and 12" round sewer pipes, Teledyne Isco
offers flow metering inserts that have a built-in
bubbler and form a round orifice or v-notch weir
in the flow stream. An inflatable rubber
bladder keeps the insert firmly seated inside
the round pipe. The inserts should not be
considered permanent, as they do place a
restriction in the pipe and are subject to
clogging.
Figure 1-1 Flow Metering Insert Diagram
Bubble Line
Handle
Round Orifice
Air Line
Rubber Bladder
Bubbler

Section 1 Getting Started
1-9
1.3.2 Connection to a Sampler
A 4230 Flow Meter can control a sampler in a
flow-proportional sampling mode. This means
the sampler will take a sample after a specific
volume has passed through the flow stream,
rather than after a particular interval of time.
In this mode, the sampler and flow meter can
compensate for varying flow rates. You can use
the 4230 Flow Meter with Isco samplers or
samplers made by others.
Connecting an Isco Sampler to a 4230 Flow
Meter requires an Isco flow meter-to-sampler
connect cable. The cable is 25 feet long. If you
plan to use the sampler enable feature (see
Section 2 - Programming), make sure you use
the newer cable that has all six pins connected.
Older cables do not have a connection between
the F pins and this keeps sampler enabling
from working. If in doubt, use an ohmmeter or
continuity checker to test your cable.
1.3.3 Adjusting Level
Generally, you measure the level in the flow
stream with a gauge. Make this measurement
accurately, as the level setting on the flow
meter will determine the accuracy of all
subsequent level and flow rate measurements
made by the flow meter. When you are satisfied
that the flow stream has been measured
accurately, you can change the level reading on
the flow meter to show this reading.
First, make sure the bubble line is properly
installed and set at or below the “zero” point in

4230 Bubbler Flow Meter
1-10
the flow stream. Then set the level by selecting
Adjust Level/Parameters step in the flow meter
program. You may then adjust the level by
entering the measured level value through the
number keys. When the proper value is
displayed, enter the number into memory by
pressing the Enter/Program Step key.
Note
It is very important that you measure the level in the
stream accurately, as all subsequent calculations of flow
will be based on this measurement. If the level value
entered is incorrect, all subsequent flow calculations will
be incorrect also.
1.3.4 Data Acquisition and Storage
(Flowlink®)
As mentioned in previously, all 4230 Flow
Meters contain memory you can allocate to
store level, rainfall, and sample data. You can
interrogate this information for later
processing. To set up the flow meter’s memory
for data storage, you must use Flowlink,
Teledyne Isco’s proprietary data acquisition
and processing software. Programs from
Flowlink allow you to set up the flow meter for
memory initialization. data acquisition, and
interrogation from a different location through
an IBM PC®compatible computer. The
computer and the flow meter connect together
through a standard dialup telephone line with
modems. (The modem in the flow meter is an
optional accessory.) Multiple flow meters can be
initialized and interrogated by the same

Section 1 Getting Started
1-11
computer. You can also use Flowlink to access
the flow meter at the installation site with a
laptop computer plugged into the Interrogator
connector on the flow meter. Other programs in
Flowlink allow the processing of the data
retrieved from the flow meter. Refer to the
Flowlink manual for further information.
Note
Storage of data is not automatic in the 4230 Flow Meter.
You must use programs from Flowlink software to
initialize, partition, and size the memory, and also to
retrieve the stored data.
Figure 1-2 Recommended level measurement
method
Note
Note that you are actually measuring the distance from
the top center of the pipe to the surface of the flow
stream. The level (h), then is the distance from the top
center of the pipe, d, subtracted from the diameter of
the pipe, D. You must know the correct diameter of the
pipe.
D
d
h
D – d = h (level)

4230 Bubbler Flow Meter
1-12
1.3.5 Parameter Sensing with the 4230 Flow
Meter
The 4230 Flow Meter also has the capability of
displaying, recording, and (if Flowlink software
is used) storing data from parameter sensors.
The sensors available from Teledyne Isco for
the 4230 Flow Meter measure temperature, pH
(the relative acidity or alkalinity of a solution)
and D.O. (dissolved oxygen). The YSI Model 600
Multiparameter Sonde offers pH, D.O.,
temperature, and conductivity. You can also
measure and record rainfall with the Isco 674
Tipping Bucket Rain Gauge, which connects to
its own port on the flow meter.
All parameter probes require constant and
complete submersion in the flow stream for
proper operation. Dry operation can damage
the pH and D.O. probes. The pH and D.O.
probes are extremely sensitive devices and
require the use of the 201 pH Module and 270
D.O. Modules (signal amplifiers) between the
probes and the flow meter. The modules are not
interchangeable.
Note
The 270 D.O. module has been discontinued. Probes,
service kits, and accessories are still available to
maintain existing field units.
The probes can be installed in a variety of
places, but typical installation is in round pipes.
Teledyne Isco offers a series of rings that
provide simplified mounting for all probes
inside round pipes.

Section 1 Getting Started
1-13
Each probe snap-mounts to a specialized sensor
carrier.
• The sensor carrier then attaches to the
mounting rings by sliding tabs into
mating slots.
• The probe cable is routed from the
stream to the parameter module.
• The module is installed and its cable
routed to the flow meter’s Parameters
connector.
Figure 1-3 YSI 600 Multi-Parameter Sonde
(End cover removed to show
sensors)
Note
The 4230 Flow Meter has only one parameter sensing
port. You must select temperature, D.O. with
temperature, or pH with temperature. (D.O. and pH
require temperature monitoring for proper operation.) If
Temperature Sensor
pH Sensor
pH Reference
D.O. Sensor
Conductivity
(inside)

4230 Bubbler Flow Meter
1-14
you want to change your selection later, you can. You
will need the correct probe and module and you will
have to change the program in the flow meter.
Note
All brands or product names used in this text are
trademarks or registered trademarks, and are the
property of their respective companies or organizations.