42213 Sarah Way, Temecula, CA 92590,
Tel: 800-854-8530 (USA)
Micro Series Frequency,
& Period Meters
With dual, independently field-scalable
- Available in three digit heights:
0.56" for panel mounting,
5.0" (Mighty-5) for
- Two independently field-scalable
channels selected by front panel pushbutton
- Frequency from 0.005 Hz to
- Inputs from NPN or PNP proximity
switches, contact closures, digital logic, magnetic pickups down to 12 mV, or AC inputs up
to 250 Vac
- 6-digit resolution at update
rates up to 25/s
- Line frequency measurement to
60.0000 in a few line cycles
- Selectable "count by"
of 10 or 100 with rounding
- Square root extraction
- Isolated 5, 10 or 24 Vdc
excitation supply to power sensors
- Green or red LED display
- Choice of isolated plug-in
options for control and computer interface:
4-20 mA & 0-10
V analog output,
RS232/485 serial I/O,
low voltage AC & DC power
case environmentally sealed to NEMA-4X from front panel.
- 1/8 DIN
version certified to UL 3101-1, CAN/CSA-C22.2,
EN 61010-1 (CE Mark).
of the Standard Counter, plus:
- Rate and total simultaneously.
- Custom curve
- Arithmetic functions
applied to two channels: A+B, A-B,
A*B, A/B, A/B-1 (draw).
Micro dual-channel frequency, rate and period meter is a basic
operating mode of the Micro counter with the FR signal conditioner board. It can
display frequency from 0.005 Hz to 1 MHz, rate in engineering units, and period (inverse of
frequency). The normal displayed value can range up to 999,999 counts. Above that level,
the display will flash and go into four-digit XXXXEX scientific notation. Square root
extraction is standard. Each
channel (A or B) may be independently scaled for frequency, rate or period. The displayed
channel is selected via a front panel pushbutton.
Examples of applications are the accurate display of AC
line frequency, RPM, speed from proximity switch inputs, and flow from turbine flowmeter
Fast, High Resolution Measurement
The Micro frequency /
rate meter determines
frequency by timing an integral number of periods over a specified gate time, and then
taking the inverse of period. Rate is obtained by multiplying the input by a scale factor.
The inverse period approach allows greater accuracy and faster update times than
conventional meters which count signal pulses over a specified time interval. AC line
frequency may be accurately measured to 50.0000 or 60.0000 Hz in a few line cycles. 1000 Hz
signals may be measured to 0.01 Hz resolution at up to 25 readings per second. Fast response is
ideal for alarm and control applications.
To reduce the effects of signal noise, a count
by 10 or 100 feature with rounding is selectable. Variations in the displayed reading can
also be reduced by selecting a longer gate time. An adaptive filter can reduce variations
due to noise while rapidly responding to actual changes in the signal.
An Extended counter
version provides capabilities beyond those of the standard counter:
Rate and total simultaneously.
channel can display total while the other displays rate. The selection for either channel
is via a front panel pushbutton. This mode is ideal for flow applications when the same
signal is applied to both channels.
accurate custom curve linearization allows linearization of the low end of
turbine flowmeters. For setup, up to 240 data points can be input into a spreadsheet or
text file by the user. The computer then calculates nonlinear segments, which are
downloaded into the meter via RS232. The Extended version allows linearized rates to be
Arithmetic functions. The
Extended counter makes arithmetic functions available, namely A+B, A-B, A*B, A/B and A/B-1
(draw). For example, A+B allows two input flows to be summed for total flow, while A-B
allows outflow to be subtracted from inflow for net flow. If transducers with a frequency
output are used, A*B allows horsepower to be displayed based measured torque and RPM, or
based on force and velocity. A/B can be used for the proper mixing of ingredients, while
A/B-1 (draw) is used to compare rates for stretching or tensioning.
The dual-channel signal
conditioner accepts inputs from proximity switches with PNP or NPN output, TTL or CMOS
logic, magnetic pickups, contact closures, low-level outputs from turbine flow meters down
to 12 mV, and high-level AC line inputs up to 250 Vac.
built-in isolated 5, 10, or 24 Vdc excitation supply can power proximity switches and
other sensors, thus eliminating the need for an external power supply.
Other Features and Options
controller, and RS232/485 serial communications boards can upgrade Micro
and Mighty Series meters
from stand-alone monitor to system interface and control. With the
optional analog output board, a Micro frequency / rate meter can serve
as a 0-10 V or 4-20 mA transmitter.
instruments can be powered from
95-240 Vac ±10% and 95-370 Vdc, or
optionally from 12-34 Vac and 10-48 Vdc.
Any setup functions and front panel keys may be locked out for
simplified usage and security. The popular
DIN version with 0.56" high digits is environmentally sealed to
NEMA-4X (IP65) from the front when panel mounted, and is
available with red or green LEDs.
6 digits, 7-segment
Available with 0.56", 1.0", 4.0" or 5.0" digits.
High brightness red. Green available with 0.56" digits.
-999999 to +999999,
XXXXEX scientific notation beyond 999999
Four LED lamps
Channel A Frequency
Channel B Frequency
AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups
Common ground for channels A & B
0.005 Hz to 1 MHz
0.005 Hz to 250 kHz
-12 mV to +12 mV, +30 mV to +60 mV, -30 mV to -20 mV,
-150 mV to +150 mV, +350 mV to +600 mV, -600 mV to -350 mV,
-1.15 V to +1.15 V, +1.25 V to +2.1 V, -2.1 V to -1.25 V
Selectable: 1 MHz, 30 kHz, 250 Hz
Selectable: 0, 3, 50 ms
Output & Display Updates
Gate time + 30 ms+ 0-2 signal periods
Selectable 10 ms to 199.99 s
Selectable 10 ms to 199.99 s
Same as conversion time
calibrated to ±2 ppm
±1 ppm/°C (typ)
95-240 Vac ±10% and 95-370 Vdc
12-34 Vac and 10-48 Vdc
DC or 49-440 Hz
Safety-rated to 250 Vac, meter ground to earth ground,
DC to 60 Hz, 4.2 kVp per High Voltage Test
Vdc ±5%, 100 mA max
10 Vdc ±5%, 120 mA max
24 Vdc ±5%, 50 mA max
50 Vdc to meter ground
0°C to 60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted
AC Line Frequency
||The Micro frequency meter will accept line voltages up to 250 Vac and
display line frequency to 6-digit accuracy (50.0000 or 60.0000) in a few line cycles. Fast
low frequency response is achieved by timing the period and taking its inverse.
RPM and Speed
||The Micro frequency meter can sense the low-level signals from magnetic
pickups or the NPN or PNP transistor output of active sensors. These can be powered
directly by the meter. Display in RPM in tachometer mode or rate in units of speed is achieved by mathematically
scaling the meter.
Flow Rate and Simultaneous Total
||The Micro frequency / rate meter is compatible with all flow
generate pulses at a frequency proportional to flow rate. The Extended version can display
scaled rate or total for the same input at the push of a button, and alarm from both the
rate and total. The Extended version can also linearize flow transducers so as to extend
their dynamic range.
Combining Two Rates
||The Extended Micro frequency / rate meter offers A+B, A-B and A/B arithmetic
functions. A+B allows two input flows to be summed for total flow, while A-B allows
outflow to be subtracted from inflow for net flow. Flow ratios aid in the proper mixing of
||The Extended Micro frequency / rate meter can linearize the output
meters, which tend to be nonlinear on the low end. Linearizing improves the
dynamic range and accuracy of turbine flow meters.
The Micro dual channel
rate meter can independently scale, display and alarm two pulse input channels. All signal
or alarm data can further be transmitted via RS232 or RS485, including peak readings and
arithmetic combinations of the two rates. The displayed rates can also be transmitted as
an isolated 4-20 mA analog output.
Micro & Mighty Series Downloads