Universal Flow Monitors FlowStream OFS User manual

FSMAN.6 081214 Page 1
™
Laminar Mass Flowmeters
User Manual
Series: OFS
Firmware Revision 5.79
UNIVERSAL FLOW MONITORS, INC.
1755 East Nine Mile Road
PO Box 249
Hazel Park, MI 48030-0249
TEL [phone] FAX [phone]
http://www.flowmeters.com

FSMAN.6 081214 Page 2
TABLE OF CONTENTS
PROPRIETARY NOTICE............................................................................................................. 3
NAMEPLATE EXAMPLE............................................................................................................ 4
GENERAL SPECIFICATIONS .................................................................................................... 5
ELECTRICAL SPECIFICATIONS............................................................................................... 6
OPERATION ................................................................................................................................. 7
Figure 1. Laminar Flow Illustration ........................................................................................... 7
APPLICATIONS ........................................................................................................................... 7
Using FlowStream at Varying Temperatures............................................................................. 7
Using FlowStream with Different Gases ................................................................................... 8
Reference Conditions for Mass Flow Measurement .................................................................. 8
WIRING DIAGRAM..................................................................................................................... 9
Wiring for 4-20mA Transmitters ............................................................................................... 9
Figure 2. Standard Transmitter Wiring ...................................................................................... 9
Figure 3. Required Supply Voltage vs. Loop Resistance......................................................... 10
Hazardous Environment Wiring............................................................................................... 10
Figure 4. Intrinsically Safe Installation ................................................................................... 11
Wiring for Voltage Output Models .......................................................................................... 12
Figure 5. Voltage Output Wiring ............................................................................................. 12
Wiring for Frequency or Pulse Output Models........................................................................ 13
Figure 6. Frequency and Pulse Output Wiring......................................................................... 13
POWER-UP ................................................................................................................................. 14
LCD READOUT.......................................................................................................................... 14
Flow Rate ................................................................................................................................. 15
Totalizer ................................................................................................................................... 15
Pressure .................................................................................................................................... 17
Temperature ............................................................................................................................. 19
USER MENU............................................................................................................................... 20
Select Response Time .............................................................................................................. 22
Sampling Delay........................................................................................................................ 23
Signal Averaging...................................................................................................................... 24
Set High Flow Alarm ............................................................................................................... 26
Set Low Flow Alarm ................................................................................................................ 28
Tare (Re-Zero) the Flowmeter ................................................................................................. 29
Scaling the Output Span........................................................................................................... 31
Selecting the Gas...................................................................................................................... 32
Totalizer ON/OFF .................................................................................................................... 33
Pulse Output Setting................................................................................................................. 34
Checking Battery Voltage ........................................................................................................ 35
SPECIAL FEATURES ................................................................................................................ 36
Factory Reset............................................................................................................................ 36
Low Supply Voltage Indicator ................................................................................................. 37
Diagnostic Mode ...................................................................................................................... 38
HOW TO ORDER A SINGLE-GAS FLOWMETER ................................................................. 40
DIMENSIONS OF OFS SERIES ................................................................................................ 42
RETURN MATERIAL AUTHORIZATION ............................................................................... 43
WARRANTY INFORMATION .................................................................................................. 45

FSMAN.6 081214 Page 3
PROPRIETARY NOTICE
The information contained in this publication is derived in part from proprietary and patented
data. This information has been prepared for the express purpose of assisting in installation,
operation, and maintenance of the instruments described herein. Publication of this information
does not convey any rights of use or reproduction other than in connection with the installation,
operation and maintenance of the equipment described herein. Universal Flow Monitors, Inc.
reserves the right to change the information contained in this publication at any time and without
prior notice.
Serial numbers are formatted as YY MM ID 000
YY = year, MM = month, ID = product identifier, 000 through 999 = three-digit sequential
number.

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NAMEPLATE EXAMPLE
The Intrinsically Safe flow transmitters have the following label:
Intrinsically Safe
flowmeters must include
“X2A” or “Z2A” in the
Model Code
Firmware revision
Model Code

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GENERAL SPECIFICATIONS
Flow Ranges: 500 SCCM full-scale to 1,000 SLPM full-scale
1 SCFH full-scale to 2,100 SCFH full-scale
Turndown Ratio: 100:1
Maximum Operating Pressure: 100 PSIG
Burst Pressure: 200 PSIG
Pressure Effect on Accuracy: Less than 0.03% F.S. / PSI
Maximum Operating Temperature: 176 °F (80 ºC)
Minimum Operating Temperature: -13 °F (-25 ºC)
Temperature Effect on Accuracy: Less than 0.03% F.S./ °F
Maximum Pressure Drop: 1.5 PSI at F.S. flow (from inlet port to outlet port)
Process Connections: 1/4”-3/8”-1/2”-3/4” NPT female
Wetted Parts
Sensors: Glass-filled nylon, alumina-based ceramic, silicon, gold,
epoxy
Flow Body Internals: Anodized aluminum, Viton, stainless steel
Enclosure Rating: Type 4
Display: 4-digit LCD digital display, 0.35" high
Approvals: CE, CSA, Intrinsic Safety (all classes and divisions) with
proper zener barrier

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ELECTRICAL SPECIFICATIONS
Accuracy (Including Linearity and Repeatability)
Flow: ± 1% of full-scale for flowmeters sized from 15-566 SLPM
(31-1200 SCFH) of Air
± 2% of full-scale for flowmeters sized for lower than
15 SLPM (30 SCFH) of Air
± 2% of full-scale for flowmeters sized for higher than
566 SLPM (1201 SCFH) of Air
Pressure: ± 1 PSI (See Note 1)
Temperature: ± 3 °F
Totalizer: ± 0.25% of full-scale (in addition to flow accuracy)
Output Signal
Analog: 4-20 mA (2-wire loop powered)
0-5 V, 0-10 V, 1-5 V
0-5 V Bi-directional (2.5 V = 0 flow)
Frequency: 0-1000 Hz, 200-1200 Hz
0-3V signal amplitude
Pulse: 1,250-5,000 pulses/minute, user selectable
0-3V pulse amplitude
2 msec pulse width
Response Time: 5 –100 msec (step response), user selectable
Alarms: 2 independent open-collector outputs (high/low flow rate)
with corresponding LEDs
Open-Collector Rating: 30VDC at 50 mA
Electrical Connection: 4- or 7-conductor shielded pigtail cable
Supply Voltage: 10–30 VDC (Standard), 12-24 VDC (Intrinsically Safe)
7.2-9 VDC for battery-operated units (See Note 2)
Supply Current: 22 mA @ F.S. flow (includes over-range) for 4-20 mA
loop-powered transmitters
5 mA for voltage, frequency, and pulse outputs
3.5 mA for battery-operated units (See Note 2)
Note 1: Pressure, temperature, and totalizer are only displayed on the LCD. No output signal is
available for these parameters.
Note 2: Battery-operated units require a standard 9V alkaline battery and will operate for over 100 hours
continuously. An On/Off switch allows the user to turn the power off, thus conserving the battery life.
These flowmeters have no output signal.

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OPERATION
FlowStream flowmeters accurately measure the mass flow rate of most gases. The flow rate is
determined by measuring the pressure drop across a unique internal restriction, known as
Laminar Flow Element (LFE). The restriction is designed such that the gas molecules are forced
into moving in parallel paths along the entire length of the passage for the entire range of
operation of the device. Unlike other pressure-flow measuring devices, the relationship between
pressure drop and flow is linear in laminar flowmeters.
FlowStream mass flowmeters utilize an absolute pressure sensor along with a temperature
sensor to compensate for density variations of the gas. When combined with the differential
pressure (volumetric flow) output, the mass flow rate of the gas can be determined.
Figure 1. Laminar Flow Illustration
APPLICATIONS
FlowStream flowmeters are designed to work with non-corrosive, non-ionic, clean, dry gases
only. Introduction of liquids to the internal sensors will damage the unit, and the repair is not
covered under warranty. Relative humidity of the gas can be as high as 100%, as long as proper
installation guarantees that no internal condensation will occur. A 50-micron filter and/or dryer
may be required for some applications.
Using FlowStream at Varying Temperatures
Even though FlowStream flowmeters measure true mass flow, rapid variations in ambient
and/or gas temperature may affect performance. This is due to the time lag of the internal
temperature sensor and the slow heating and cooling of the flowmeter body. It is highly
recommended that through proper installation the following two objectives be met:
There be minimal difference between gas temperature and ambient temperature;
Rapid temperature variations be avoided.

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The internal temperature sensor is located above the inlet port, very close to where the gas enters
the meter. This ensures accurate measurement of the gas temperature. However, because the
temperature sensor is embedded inside the flowmeter body, if ambient temperature is different
from gas temperature, there would be a discrepancy between what the sensor reads and the true
gas temperature. The flowmeter body would track ambient temperature while gas temperature
would heat/cool the body at a different rate.
Likewise, if temperature variation is rapid, the flowmeter body may not follow it quickly enough
due to the mass of the metal flow chamber, which in turn would result in inaccurate
measurement of gas temperature.
For optimal performance, always allow two to four hours from the time the ambient and gas
temperatures are stabilized to when the first flowmeter reading is taken.
Using FlowStream with Different Gases
FlowStream flowmeters can easily be used to measure the flow rate of other gases, as long as
the gas compatibility criteria are observed. For example, a flowmeter that is factory-calibrated
for air can be used to measure the flow of Argon. (Consult Factory for additional information.)
Reference Conditions for Mass Flow Measurement
Although the correct units for mass are expressed in grams, kilograms, etc., it has become
somewhat standard that mass flow rate is specified in SLPM (standard liters per minute), SCFH
(standard cubic feet per hour) or other similar units.
This means that the mass flow rate is calculated by normalizing the volumetric flow rate to some
standard temperature and pressure (STP). By knowing the gas density at that STP, one can
determine the mass flow rate in grams per minute, kilograms per hour, etc. STP is usually
specified at sea level conditions; however, no single standard exists for this convention. UFM
uses STP of 70° F and 14.7 PSIA.
Note: If used outside the parameters specified in this manual, the proper operation of the
flowmeter cannot be guaranteed.

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WIRING DIAGRAM
Wiring for 4-20mA Transmitters
Figure 2 shows a typical 2-wire, 4-20mA transmitter wiring for use with FlowStream
flowmeters. Maximum loop resistance is related to the available supply voltage. Since the
flowmeter requires 10 volts to operate, the voltage drop across the loop resistance at full-scale
flow output (20mA) must be added in to determine the minimum supply voltage. For example,
if a 100-ohm resistor is used to convert the current signal to voltage, the voltage drop across the
resistor will be 0.4-2 volts for 4-20 mA, respectively. Minimum required loop voltage in this
case is 12 volts, as shown. Likewise, the voltage drop for a 250-ohm resistor is 1-5 volts,
requiring a minimum of 15 volts supply. Please refer to the graph in Figure 3.
Wire Color
Function
Red
Supply +
12-30VDC (Standard)
12-24 VDC (Intrinsically Safe)
Black
Supply -
DC GND
Brown
Tare
Short to GND for 5 seconds to tare at zero
flow
White
Not Used
Do not connect
Shield
Internally Grounded to
Chassis
Blue
High Alarm Output
Open-collector
Orange
Low Alarm Output
Open-collector
Green
Alarm Common
Emitter for both alarms
Figure 2. Standard Transmitter Wiring
(DO NOT Use for Intrinsically Safe Applications)
Note: Shield wire (shown as gray) may be connected to an external chassis ground to improve
electrical noise immunity. However, care must be taken not to connect this ground to signal
ground.

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Figure 3. Required Supply Voltage vs. Loop Resistance
Hazardous Environment Wiring
Intrinsically Safe wiring must be installed in accordance with Article 504 of NEC, ANSI NPF 70
and Control Drawing Number 7577, Revision 00 (Figure 4, below). The transmitter approval
by the Canadian Standards Association for installation in Hazardous environments is based on
installation through an Intrinsic Safety Barrier.
The Transmitter when wired through the I.S. Barrier is suitable for use in:
CLASS I GROUPS A, B, C & D
CLASS II GROUPS E, F & G
CLASS III HAZARDOUS LOCATIONS
Earth Ground of the I.S. Barrier must be connected to the earth ground of the AC feeder supply.
The resistance between Intrinsically Safe ground terminals and A.C. Earth ground must be less
than one Ohm. (UFM suggested I.S. Barrier R.Stahl 9001/01-280-075-10, UFM part number
8140).
The Power Supply voltage is limited to 24 VDC Max. The Power Supply Control Unit must not
use or be able to generate more than 250 volts. The Maximum Load that can be put on the
system is 250 Ohms.
All repairs on the Flow Transmitter should be accomplished at the factory because any
substitution of components may impair Intrinsic Safety.