Dwyer TM2 User Manual

Series TM2 Digital Rate Meter & Totalizer

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Specifications - Installation and Operating Instructions

Bulletin F-41-TM2

Monitor flow rate or total flow with Model TM2 Flow Totalizer

Unit features a four digit flow rate display and an eight digit total­izing display with a programmable, five position decimal point.
Easily toggle between rate and total with front-panel push-button.
Use scaling factor to define flow rate in engineering units such as
mL/min, L/min, or gal/hr.

Section I. UNPACKING YOUR DISPLAY

Checking for external damage to shipment

Your Model TM2 Display was packed by the manufacturer in
such a way that you should receive it with no damage. If external
damage is noted upon receipt of the package, please contact the
shipping company (not Dwyer Instrument, Inc.) immediately.
Dwyer Instruments, Inc. will not be liable for damage to the
meter once it has left the manufacturing premises.

Unpacking the display

After external inspection of the product, proceed to open the
package from the top, taking care not to cut too deep. Remove
all documentation (if any) resting on top of the packing peanuts.
Inspect all products for concealed shipping damage. If damage
is noted, please contact the shipping carrier and/or Dwyer
Instruments, Inc. to resolve the problem.
When unpacking the products from the shipment, please take
care to remove all products from the box. check thoroughly for
extra cables, power adapters, and other options listed on the
packing slip, if any.

.

SPECIFICATIONS
Input: 7.5 VDC max. pulse.
Accuracy: ±0.2%.
Input Impedance: 27 k Ω at 3 VDC.
Totalizer Type: UP count.
Rate Indication Type: Frequency.
Count Input Speed: 10 kHz @ 50% duty cycle.
Totalizing Range: 0.0001 to 100.0000 with five position

decimal point.
Rate Indication Range: 0.001 to 9999 (five position decimal
point).

Update Time: 0.7 seconds.
Display: 8-digit LCD, 7/16" H.
Temperature Limits: 32 to 131°F (0 to 55°C).
Housing Material: Cycolac X-17.
Power: One 3V lithium battery (included).
Average Battery Life: Approximately 5 years.
Weight: 1 Ib (0.5 kg).
Agency Approvals: CE.

Cautions against damaging the unit

Any damage inflicted on the display by the customer will not be
repaired under warranty by Dwyer Instruments, Inc. See Section
6 for more information.

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: [phone] e-mail: [e-mail]

Phone: [phone] www.dwyer-inst.com

Section II. INSTALLING YOUR MODEL TM2

Mounting the display

When choosing a place to mount the display, keep these three
things in mind:

a. The display should not be mounted near a solenoid or

other inductive device.

b. Enough ventilation should be supplied to keep the

totalizer operating within the temperature
specifications (see Selection 5).

c. This display should not be mounted in a heavy

vibration area.

The recommended mount for the Model TM2 display is panel­mount. The recommended panel cutout for the display is 2.677˝
wide (68 mm) by 1.299˝ tall (33 mm).

To install the unit in a panel, first remove the two fasteners
located on the side of the unit. These slide tightly in grooves and
should slide out without too much trouble. DO NOT MISPLACE
THESE FASTENERS!!!

With the fasteners removed, the display should slide into the
panel cutout. The included gasket should be between the panel
and the face of the display. Making sure the gasket is properly
aligned and not twisted, slide the display in place. Reinstall the
fasteners by sliding them in their grooves until they stop. The
screws on the fasteners should be facing the panel and the head
of the screw facing away from the panel.

Tighten the set screws of the fasteners using a flathead
screwdriver in a clockwise motion. They should be equally
tightened until the display is snug and the gasket is reasonably
compressed.

Pin #4: This pin is used for remote reset. When

momentarily connected to ground, this pin will
reset the totalizer just like the front panel reset
button.

Pin #5: This pin is used to enter program mode. When

connected to the ground, the Model TM2 enters
program mode, described in Section 3.

Pin #6-Pin #8: These pins are not functional.

See the last page for wiring diagrams of connections to various
Flo-Sensors and other products.

Wiring Recommendations

Following these suggestions will increase noise immunity and
lengthen unit life.

Cable: The connection between the count source and the
totalizer/ratemeter should be made with a two-conductor
shielded cable. The shield should be connected to earth ground
at one end only. The connecting cable should not be run in
conduits with cables switching high inductive loads.

Relay Coil Suppression: If a relay contact is used as a count
source, the relay coil should be suppressed. This can be
accomplished with an RC network for AC coils or a diode for DC
coils.

Mounting: This totalizer/ratemeter should not be mounted near a
solenoid or other inductive devices. Enough ventilation should
be supplied to keep the totalizer operating within the temperature
specifications. Do not mount this unit in a heavy vibration area.

When mounted with the provided fasteners, gasket, and specific
rectangular panel cutout, the Model TM2 display achieves a
NEMA-4X rating.

Electrical connections to the display

The Model TM2 is self-powered using an internal lithium battery,
thus there is no need for external power. The typical life of this
battery is 5 years.

After connections are made, power the display by removing the
temporary insulator on the back of the unit. Simply pull the white
tab out -- there is no need to open the battery cover.

Pin #1

Signal &
Reset
Ground

Pin #1: This pin should be connected to the ground of the

Pin #2: This pin is not used with any Dwyer Instruments,

Pin #3: This is the pulse signal input. The Model TM2

Pin #2

Not Used

pulse signal. In most cases, this will be the same
as the ground of the Flo-Sensor that the Model
TM2 Display is connected to.

Inc. products.

accepts all TF10xx Series Flo-Sensor pulse
outputs. These are 7.5VDC peak squarewave
pulses directly proportional to the flow rate.

Pin #3

Signal In
(Pulse Input)

Pin #4

Remote
Reset
(optional)

Pin #5

Enable
Program
Mode

Section III. PROGRAMMING THE TM2

The Dwyer Instruments, Inc. Model TM2 Display is a versatile
meter that will indicate flow rates and totalize flow in virtually any
unit of measurement. To do this, it uses 2 numerical factors
(programmed by the user) to customize and match each display
with each particular Flo-Sensor.

To successfully program this display, you must first understand
how it works and what you are programming into it. Program
mode uses six different screens to program rate and total flow.
They are used as follows:

TOTALIZER FUNCTION:

Screen #1: The Significant digits of the Totalizer Multiplier

are entered here. The Model TM2 uses these
to calculate total flow.

Screen #2: This screen is simply a decimal placer. Since

only the significant digits of the Totalizer
Multiplier are entered in screen #1, this allows
you to make up for the insignificant zeros not
entered there.

RATE FUNCTION:

Screen #3: The significant digits of the Rate Multiplier are

entered here. The Model TM2 uses these to
calculate current rate of flow.

Screen #4: This screen is another decimal placer. Since

only the significant digits of the Rate Multiplier
are entered in screen #3, this allows you to
make up for the insignificant zeros not entered
there.

MISCELLANEOUS:

Screen #5: This screen should always read “1”. It is not

used with any Model TF10xx Flo-Sensors.

Screen #6: This screen enables/disables the front panel

reset button.

To understand the insignificant/significant digit importance, you
must understand that many of your Rate and Totalizer Multipliers
will be very small, with several zeros in front of them, such as

0.0001234. However, screens 1 and 3, where those numbers are
entered, will only allow 6 to 4 digits, respectively. There is,
therefore, no room for those preceding zeros. For each zero
removed, the decimal place in the following screen shifts one
left. This is further described in Section 3. d.

Since the Model TM2 operates on pulse inputs, the pulse output
(frequency) of the Flo-Sensor at 100% flow must be determined.
This number is located in one of three places:

1. On a tag attached to a fitting of the Flo-Sensor

2. On a calibration data sheet, included with the
Flo-Sensor

3. On a label near the connector of the Flo-Sensor

The label should provide pulse output (PPS) information of the
particular Flo-Sensor at the rated 100% flow of the Flo-Sensor.
For example, for a Model TF1032 Flo-Sensor, rated from 0.1 to

2.0 L/min, you would need the pulse output data of that Flo­Sensor at 2.0 L/min. (The pulse output is usually given when the
voltage output is 5.00 VDC, or 100% flow.)

Note: If the tag listing the pulse rate is missing, please contact
Dwyer Instruments, Inc. for pulse output information on that
particular Flo-Sensor. Please provide the model number, serial
number, and flow range of the Flo-Sensor you are requesting
information on. It is also possible to determine the pulse output
frequency by using a volt meter and the Model TM2 together.
Using methods of programming described in Section 3.d, set
screen #3 to read “1.000” and screen #4 to read “0000”. Hook
the volt meter up to the analog voltage output of the Flo-Sensor.
Using the voltage output as a guide, provide enough flow
through the sensor to wear the sensor outputs 5.00 VDC. Place
the TM2 in rate mode and the number displayed will be the pulse
output of the sensor at 100% rated flow.

Figuring the Rate Multipler

The Rate Multiplier is the number that the Model TM2 uses to
interpret pulses into rate. To determine this factor, first convert
the 100% flow rate of the Flo-Sensor (listed in the manual of the
Flo-Sensor) into the units in which you wish the Model TM2 to
display rate. Use the following formula to figure the Rate
Multiplier:

100% Rated Flow

Time Unit New Time Unit Factor Pulse Output (PPS)

where 100% Rated Flow = 100% flow rate of Flo-Sensor, where
pulse output is given (Ex: 2.0L)

Time Units = time units of 100% Rated Flow (Ex: 1 min.)
Pulse Output = marked pulse output of sensor at 100%
Flow (PPS)
New Flow Unit Factor = see table on the next page
New Time Unit Factor = see table on the next page

New Flow Unit Factor 1

X

X

Entering Program Mode

In order to program the factors into the display, it must first be put
into program mode (of course, the unit must be powered, see
Section 2.b). To do this, simply connect the ground input (pin #1)
to the enable program input (pin #5) with a short wire, jumper, or
alligator chip. Make sure the connection will hold well enough for
you to program a series of numbers into the unit. When you are
finished and wish to exit program mode, simply remove the
connection.