Agilent Technologies Flow Tracker Series User manual

Agilent Technologies
Agilent
Flow Tracker Series
1000/2000
Reference Manual

2Reference Manual
Notices
© Agilent Technologies, Inc. 2002
No part of this manual may be reproduced in
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tronic storage and retrieval or translation
into a foreign language) without prior agree-
ment and written consent from Agilent
Technologies, Inc. as governed by United
States and international copyright laws.
Microsoft ® is a U.S. registered trademark
of Microsoft Corporation.
Edition
Second edition, May 2002
First edition, August 2001
Printed in USA
Agilent Technologies, Inc.
2850 Centerville Road
Wilmington, DE 19808-1610 USA
Safety Notices
CAUTION
A CAUTION notice denotes a haz-
ard. It calls attention to an operat-
ing procedure, practice, or the like
that, if not correctly performed or
adhered to, could result in damage
to the product or loss of important
data. Do not proceed beyond a
CAUTION notice until the indicated
conditions are fully understood and
met.
WARNING
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly per-
formed or adhered to, could result
in personal injury or death. Do not
proceed beyond a WARNING
notice until the indicated condi-
tions are fully understood and
met.

3
Agilent Flow Tracker Series 1000/2000
Reference Manual
Agilent Technologies
Flow Tracker Series 1000/2000
Safety Information 4
Installation 6
Flow Measurement Operating Principle 9
Basic Operation 10
Operating Modes 14
RS-232 Output 29
Maintenance and Recalibration 32
Flow Tracker 1000/2000 Flow Measurement Specifications 34
Flow Tracker 2000 Leak Detector Specifications 35
The Agilent Flow Tracker 1000 and 2000 Series Gas
Chromatography flowmeters are designed to provide useful
flow information in one simple, reliable, and portable
instrument. The Flow Tracker 1000 has two operating modes,
Flow mode and Gas Chromatography (GC) mode. The Flow
Tracker 2000 has an additional Leak Detector mode and
incorporates a separate, built–in sampling pump and probe.
The Flow Tracker data presentation format uses a multi-line
LCD display that allows simultaneous viewing of all parameters
associated with the current operating mode. Selected
parameters can be brought to the enlarged “Primary Data”
position to simplify viewing of the parameter in which the user
is most interested at any given time.
The Flow Tracker RS-232 output allows data from the current
operating mode to be streamed in real-time to a laptop
computer for collection or analysis without specialized
software.

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Flow Tracker Series 1000/2000
Safety Information
General
For indoor use only. This product should not be used in
hazardous locations. This product is rated as Safety Class II,
Installation category II, and Pollution Degree 2. If this
equipment is used in a manner not specified, the protection
of the equipment may be impaired. Agilent Technologies
assumes no liability for the customer’s failure to comply with
these requirements.
• Operating temperature range is 10—50 °C.
• Operating humidity range is 0—90% RH (noncondensing).
• Maximum recommended altitude is 15,000 ft.
Electromagnetic compatability
This device has been tested and found to comply with the limits
of CISPR 11. These limits are designed to provide reasonable
protection against harmful interference in an installation. This
equipment generates, uses, and can radiate radio frequency
energy. If not installed and used in accordance with the
instructions, this device may cause harmful interference to
radio or television reception. This can be determined by turning
the equipment off and on. The user is encouraged to try to
correct any interference by taking one or more of the following
measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and the
receiver.
•Connect the equipment into an outlet on a circuit different
from that to which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for
help.
Unauthorized modification or installation of this equipment
may invalidate the user’s ability to operate this equipment.

Flow Tracker Series 1000/2000
Reference Manual 5
This ISM device complies with Canadian ICES-001.
Cet appareil ISM est conforme a la norme NMB-001 du Canada.
This device is CE marked for ISM Group 1, Class A equipment.

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Flow Tracker Series 1000/2000
Installation
The Agilent Flow Tracker Series flowmeters have standard
1/8-inch NPT (female) inlet and outlet fittings as shown in
Figure 1. To prevent possible clogging of the internal structure,
it is recommended that a 20-micron filter be installed upstream
of the flowmeter. The unit is packaged with simple plastic hose
barbs for your convenience, however any fitting that is
appropriate for the application can be substituted.
Figure 1 Connections
RS-232 plug
Leak sampling probe
(Flow Tracker 2000 only)
AC adapter plug
Exhaust
Flow
Sample exhaust
(Flow Tracker 2000 only)
Probe receptacle
RS-232 jack
P1 100 psi
≤

Flow Tracker Series 1000/2000
Reference Manual 7
Maximum operating line pressure is 100 PSIG (690 kPa) If the
line pressure is higher than 100 PSIG (690 kPa), a pressure
regulator must be used upstream from the flowmeter to reduce
the pressure to 100 PSIG (690 kPa) or less. Although the
flowmeter’s operation is unidirectional, reversing the direction
of the flow will not inflict any damage as long as the maximum
specified limits are not exceeded. The differential pressure
sensor used in the Flow Tracker is a very sensitive device
capable of detecting minute differences in pressure.
RS-232 output cable The Agilent Flow Trackers are equipped
with an 8-pin mini-DIN data output jack located as shown in
Figure 1. The included data cable plugs into this jack with the
flat on the cable plug towards the back of the flowmeter. If the
serial port on your computer is female, the flowmeter can
simply be plugged into your serial port via the included 8-pin
mini-DIN to DB-9 serial adapter cable. If the serial port on your
computer is male, you will need a common double–ended
female adapter cable.
CAUTION When installing fittings into the NPT ports, do not exceed 12 ft-lbs of
torque.
NOTE Use of pipe dopes and sealants on the NPT ports can cause permanent
damage to the flowmeter should they get into the flow stream. If a thread
sealing tape is required, avoid wrapping the first thread or two to minimize
the possibility of getting a piece of shredded tape into the flow stream.
When changing fittings, always clean any tape out of the threads that may
come loose and enter the flow stream.
CAUTION Exceeding the maximum specified line pressure may cause permanent
damage to the solid-state differential pressure transducer. Avoid
installations (such as snap–acting solenoid valves upstream) that
apply instantaneous high pressure to the flowmeter as permanent
damage to the differential pressure sensor could result.

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Flow Tracker Series 1000/2000
Power/batteries Power is supplied by six (6) standard AA size
batteries or by an optional AC/DC adapter (Part number
5183-4781). New batteries can provide power for several days of
continuous operation depending on the quality of the batteries
and whether the leak sampling pump (Flow Tracker 2000) is
used. The power adapter jack is located as shown in Figure 1. A
P-5 style, positive center 6-15 Vdc adapter rated for at least
100 mA is required.
To install the batteries:
1Remove the flexible boot from the flowmeter housing.
2Remove all three screws from the back cover.
3Carefully remove the back cover to expose the battery
housing.
4Install the batteries as shown on the back cover.
5Replace the back cover and re-install the screws.
6Replace the flexible boot, pushing the bottom end of the
flowmeter into the boot first.
NOTE The auto-off feature automatically shuts the flowmeter off after
approximately 5 minutes of continuous no flow (less than 4 mL/min)
condition. This applies only under battery power. The auto-off feature is
disabled when power is supplied via an AC to DC adapter.

Flow Tracker Series 1000/2000
Reference Manual 9
Flow Measurement Operating Principle
The volumetric flow rate is determined by creating a pressure
drop across a unique internal restriction (known as a Laminar
Flow Element) and measuring differential pressure across it.
The restriction is designed so that the gas molecules are forced
to move in parallel paths along the entire length of the passage;
hence Laminar (streamline) flow is established for the entire
range of operation of the device.
Unlike other flow measuring devices, in laminar flowmeters the
relationship between pressure drop and flow is linear. The
underlying principle of operation of the Agilent Flow Tracker
Series flowmeters is known as the Poiseuille Equation:
Since π, r and L are constant, this equation can be rewritten as:
The second equation shows the linear relationship between
volumetric flow rate (Q), differential pressure (∆P), and
absolute viscosity (η) in a simpler form.
Q = (P1-P2)πr4/8ηL
where: Q = volumetric flow rate
P1 = static pressure at the inlet
P2 = static pressure at the outlet
r = radius of the restriction
η = (eta) absolute viscosity of the fluid or gas
L = length of the restriction
Q = K (∆P/η)
where: K= a constant factor determined by the geometry of the
restriction.

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Flow Tracker Series 1000/2000
Basic Operation
Operation of the Agilent Flow Tracker Series flowmeters is very
intuitive. The operating modes are explored in considerable
detail in the Operating Modes section.
In general, each operating mode displays all of the parameters
that are associated with that mode of operation. Each
parameter has a button associated with it and is labeled either
by a “dynamic label” on the display, or, if it is a global parameter
(a parameter which is common to all modes) the associated
button is labeled directly. The two global parameters are GAS
and MODE.
Dynamically labeled parameters are either active or passive.
Active parameters are directly affected by the flow and are
constantly changing. These parameters can be moved to the
primary display by pushing the button associated with them.
Passive parameters are usually variables that require input
from the user. The buttons associated with passive parameters
are used to select the value of the variable.
A quick overview of the operating modes and their parameters
is given in Table 1, Table 2, and Table 3.
Table 1 Flow mode (default on power up)
Parameter Label Active/Passive Button action
Line pressure PSIA Active Primary display
Gas temp °C Active Primary display
Volumetric flow Vol Active Primary display
Mass flow Mass Active Primary display (default)
Gas GAS Passive Toggles through gas list
Operating mode MODE Passive Toggles through modes

Flow Tracker Series 1000/2000
Reference Manual 11
Table 2 GC mode
Parameter Label Active/Passive Button action
Linear velocity LinVel Active Primary display (default)
Capillary inside
diameter
Dia. mm Passive Toggles through column
list
Split ratio Split Active Primary display
Reference flow Ref. Passive Sets ref. to present flow
Gas GAS Passive Toggles through gas list
Operating mode MODE Passive Toggles through modes
Table 3 Leak mode (Flow Tracker 2000 only)
Parameter Label Active/Passive Button action
Leak rate Rate Active Primary display (default)
Thermal
conductivity
Cond. Active Primary display
Relative
conductivity
Rel. Active Primary display
Sound Sound Passive Toggles sound on or off
Gas GAS Passive Toggles through gas list
Operating mode MODE Passive Toggles through modes

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Flow Tracker Series 1000/2000
Operating the Flow Tracker
1Press and hold the ON button for approximately a half
second. Two horizontal bars will appear momentarily before
the Flow mode screen appears on the display.
2Press the ZERO button to tare the flowmeter and provide it
with a reference point for zero flow. This is a very simple
but important step in obtaining accurate measurements.It
is good practice to “zero” the flowmeter each time it is turned
on. If the flow reading varies significantly from zero after an
initial tare, give the unit a minute or so to warm up and
re-zero it.
3Press GAS to scroll through the gas list. The default gas is air.
The selected gas is shown on the display under the GAS
button. The selected gas is a global parameter that stays the
same regardless of operating mode. Use this button to select
the gas presently being measured. The viscosity of the
selected gas is used in the calculation of flow.
NOTE Should the unit ever fail to come on as expected, push the OFF button and
then press and hold the ON button.
NOTE If possible, it is helpful to zero the unit near the expected operating
pressure by positively blocking the flow downstream of the flowmeter
prior to pushing the ZERO button. Zeroing the unit while there is any flow
will directly affect the accuracy by providing a false zero point. If in doubt
about whether the flow is positively blocked, remove it from the line and
positively block both ports before pressing ZERO. If the unit reads a
significant negative value when removed from the line and blocked, it is a
good indication that it was given a false zero. It is better to zero the unit at
atmospheric pressure and a confirmed no flow condition than to give it a
false zero under line pressure.
NOTE It is very important to select the gas being measured in order to get an
accurate flow rate measurement. Selectable gases are listed in Table 4.

Flow Tracker Series 1000/2000
Reference Manual 13
4Press the MODE button to switch between operating modes.
There are two operating modes (Flow and GC) in the Flow
Tracker 1000 and three operating modes (Flow, GC, and
Leak) in the Flow Tracker 2000.
5Press the OFF button to turn the unit power off from any
operating mode.
Table 4 Selectable gases
Gas Label
Air (default) Air
Nitrogen N2
Carbon dioxide CO2
Methane CH4
Hydrogen H2
95% Argon, 5% Methane mix 95% Ar 5% CH4
Helium He
NOTE The Agilent Flow Tracker Series flowmeters can also measure gases that
are not listed here. See the GC mode section for more information.

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Flow Tracker Series 1000/2000
Operating Modes
Flow mode
Flow mode is the default operating mode. The Flow mode screen
(shown in Figure 2)displays the following parameters:
Gas absolute pressure
The Flow Tracker Series flowmeters use an absolute pressure
sensor to measure the line pressure of the gas flow being
monitored. This sensor is referenced to hard vacuum and
accurately reads line pressure both above and below local
atmospheric pressure. This parameter is located in the upper
left corner of the display under the dynamic label “PSIA”. The
engineering unit associated with absolute pressure is pounds
per square inch absolute (PSIA). This can be converted to gauge
Figure 2 Flow mode screen/buttons
GAS
MODE
OFFON ZERO
Gas select
Power off
Mode
Mode indicator
Low battery indicator
Mass flow rate
Gas absolute pressure
Gas temperature
Volumetric flow rate
Primary display
(default is mass
flow rate)
Power on
Zero (tare)

Flow Tracker Series 1000/2000
Reference Manual 15
pressure (PSIG = the reading obtained by a pressure gauge that
reads zero at atmospheric pressure) by simply subtracting local
atmospheric pressure from the absolute pressure reading:
PSIG = PSIA – (Local Atmospheric Pressure)
The flowmeters use the absolute pressure of the gas in the
calculation of the mass flow rate.
Gas temperature
The Flow Tracker Series flowmeters use a temperature sensor
to measure the line temperature of the gas flow being
monitored. The temperature is displayed in engineering units of
degrees Celsius (°C). The flowmeters use the temperature of the
gas in the calculation of the mass flow rate. This parameter is
located in the upper middle portion of the display under the
dynamic label “°C”.
Volumetric flow rate
The volumetric flow rate is determined as described in the Flow
Measurement Operating Principle section. The engineering unit
associated with the volumetric flow rate is milliliters per
minute (mL/min). This parameter is located in the lower left
corner of the display over the dynamic label “Vol”. In order to
get an accurate volumetric flow rate, the gas being measured
must be selected (see Gas select). This is important because the
device calculates the flow rate based on the viscosity of the gas
at the measured temperature. If the gas being measured is not
what is selected, an incorrect value for the viscosity of the gas
will be used in the calculation of flow, and the resulting output
will be inaccurate in direct proportion to the difference in the
two gases’ viscosities.
NOTE For working in metric units, note that 1 PSI = 6.89 kPa.

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Flow Tracker Series 1000/2000
Other gases
The Agilent Flow Tracker Series flowmeters can easily be used
to measure the flow rate of gases other than those listed as long
as “non-corrosive" gas compatibility is observed. For example, a
flowmeter that has been set for air can be used to measure the
flow of oxygen.
The conversion factor needed for measuring the flow of
different gases is linear and is simply determined by the ratio of
the absolute viscosity of the gases. This factor can be calculated
as follows:
NOTE Gas viscosity, and thus gas composition, can be very important to the
accuracy of the flowmeter. Anything that has an effect on the gas viscosity
(e.g. water vapor, odorant additives, etc.) will have a direct proportional
effect on the accuracy. Selecting methane and measuring natural gas for
instance, will result in a fairly decent reading, but it is not highly accurate
because natural gas contains small and varying amounts of other gases
such as butane and propane that result in a viscosity that is somewhat
different than pure methane.
NOTE Absolute viscosity changes very little with pressure therefore a true
volumetric reading does not require a correction for pressure. Changes in
gas temperature do affect viscosity. For this reason, the Flow Tracker uses
the temperature sensor to internally compensate for this change and no
outside temperature correction is required for volumetric measurement.
Qog = Q1[η1/ηog]
where: Q1= Flow rate indicated by the flowmeter
η1= Viscosity of the calibrated gas at the measured temp.
Qog = Flow rate of the alternate gas
ηog = Viscosity of the alternate gas at the measured temp.
NOTE A good rule of thumb is “at a given flow rate, the higher the viscosity, the
higher the indicated flow.”

Flow Tracker Series 1000/2000
Reference Manual 17
Mass flow rate
The mass flow rate is the volumetric flow rate corrected to a
standard temperature and pressure (14.695 PSIA and 25 °C).
This parameter is located in the lower middle portion of the
display over the dynamic label “Mass”. The engineering unit
associated with the mass flow rate is called a standard milliliter
per minute (SmL/min). The flowmeter uses the measured
temperature and the measured absolute pressure to calculate
what the flow rate would be if the gas pressure was at
1 atmosphere and the gas temperature was 25 °C. This allows a
solid reference point for comparing one flow to another.
Volume flow vs. mass flow At room temperature and low
pressures the volumetric and mass flow rate will be nearly
identical, however, these rates can vary drastically with changes
in temperature and/or pressure because temperature and
pressure of the gas directly affects the volume. For example,
assume a volumetric flow reading was used to fill balloons with
250 mL of helium, but the incoming line ran near a furnace that
cycled on and off, intermittently heating the incoming helium.
Because the volumetric flowmeter simply measures the volume
of gas flow, all of the balloons would initially be the same size.
However, if all the balloons are placed in a room and allowed to
come to an equilibrium temperature, they would generally all
come out to be different sizes. If, on the other hand, a mass flow
reading were used to fill the balloons with 250 standard mL of
helium, the resulting balloons would initially be different sizes,
but when allowed to come to an equilibrium temperature, they
would all turn out to be the same size.
This parameter is called “corrected mass flow” because the
resulting reading has been compensated for temperature and
pressure and can therefore be tied to the mass of the gas.
Without knowing the temperature and pressure of the gas (and
thus the density), the mass of the gas cannot be determined.
Volumetric and mass flow conversion In order to convert volume
to mass, the density of the gas must be known. The relationship
between volume and mass is as follows:
Mass = Volume x Density

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Flow Tracker Series 1000/2000
The density of the gas changes with temperature and pressure
and therefore the conversion of volumetric flow rate to mass
flow rate requires knowledge of density change. Using ideal gas
laws, the effect of temperature on density is:
The change in density with pressure can also be described as:
Therefore, in order to determine mass flow rate, two correction
factors must be applied to volumetric rate: temperature effect
on density and pressure effect on density.
Although the correct units for mass are expressed in grams,
kilograms, etc. it has become standard that mass flow rate is
specified in SLPM (standard liters/minute), SCCM (standard
cubic centimeters/minute) or SmL/M (standard
milliliters/minute).
This means that mass flow rate is calculated by normalizing the
volumetric flow rate to some standard temperature and
pressure (STP). By knowing the density at that STP, one can
determine the mass flow rate in grams per minute, kilograms
per hour, etc.
STP is usually specified as the sea level conditions, however, no
single standard exists for this convention. Examples of common
reference conditions include:
ρa / ρs = Ts / Ta
where: ρa= density @ ambient condition
Ta= absolute temp @ ambient condition in Kelvin
ρs= density @ standard (reference) condition
Ts= absolute temp @ standard (reference) condition in
Kelvin
K=ºC + 273.15 (K = Kelvin)
ρa / ρs = Pa / Ps
where: ρa= density @ ambient condition
Pa= ambient absolute pressure
ρs= density @ standard (reference) condition
Ps= Absolute pressure @ standard (reference) condition

Flow Tracker Series 1000/2000
Reference Manual 19
Gas select
The selected gas is shown in the upper right hand corner of the
display. There are seven different gases commonly used for gas
chromatography that can be selected. The gas can be changed by
pushing the GAS button until the desired gas is displayed. The
selected gas is common to all operating modes and can be
changed at any time in any operating mode. The gases are
shown in Table 4.
Low battery indicator (LO BAT)
The low battery indicator, located just above the mode indicator
in the lower right corner of the display, appears if the batteries
run below a certain voltage level that can affect the accuracy of
the flowmeter.
Flow mode indicator
This indicator, located in the lower right corner of the display,
signals that the unit is in Flow mode. The operating mode can
be changed by pushing the MODE button.
0°C and 14.695 PSIA
25 °C and 14.695 PSIA
0°C and 760 torr (mmHG)
70 °F and 14.695 PSIA
68 °F and 29.92 inHG
20 °C and 760 torr (mmHG)
NOTE The Agilent Flow Tracker Series flowmeters reference 25 ºC and
14.695 PSIA (101.32 kPa).
CAUTION To avoid inaccurate readings, be sure to change the batteries when the
LO BAT indicator is displayed. Low power can result in inflated
temperature sensor readings which affect the expected gas viscosity
and mass flow calculations.

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Flow Tracker Series 1000/2000
GC mode
The GC mode screen (shown in Figure 3) displays the following
parameters:
Linear velocity
The Flow Tracker Series flowmeters use the volumetric flow
rate and the selected capillary diameter (inside diameter) to
calculate the average velocity of the selected gas through the
capillary. This parameter is located in the upper left portion of
the display under the dynamic label “LinVel”. The engineering
unit associated with the linear velocity is centimeters per
second (cm/sec). The calculation is as follows:
Linear Velocity = Volumetric Flow Rate / Capillary Area
Figure 3 GC mode screen/buttons
GAS
MODE
OFFON ZERO
Gas select
Power off
Mode
Mode indicator
Low battery indicator
Reference flow
Linear velocity
Capillary diameter
Split ratio
Primary display
(default is linear
velocity)
Power on
Zero (tare)