FSI ACM-PLUS
Selectable 2 or 3 Dimensional Current Meter
Compact, cost-effective, high-accuracy meters with
vector-averaged current speed and direction
Enhanced Design, Specifications, Performance
The Falmouth Scientific, Inc. enhanced Acoustic
Current Meter delivers extremely precise 2 or 3
dimensional velocity measurements (user selectable)
in a defined free field. The ACM-PLUS uses the most
accurate and stable current measurement techniques
available today and is configured with standard
features that are options on competitive instruments
such as extended on-board data memory, fast
download capability, high accuracy real-time
clock, and high speed data sampling.
The instrument incorporates an internal compass and
tilt sensors to provide true current vector direction.
The unit’s compact size and light weight make the
ACM-PLUS well suited for multiple meter arrays.
Windows-based software for meter setup, data
collection and data visualization make the FSI
ACM-PLUS very user-friendly.
The ACM-PLUS is available in either shallow-water or
deep-water housings. The device may also be equipped
with an optional pressure sensor, an optional CTD
module, and can be configured to log up to two analog
inputs from external sensors (e.g., DO, OBS, etc.).
FEATURES FSI ACM-PLUS-200 with optional 5 ton frame
Compact, lightweight, low-maintenance construction
User Selectable 2 or 3 axis true cosine response velocity measurement
Accurate velocity measurement with excellent low-velocity resolution
Electronic magneto-resistive compass with 2-axis tilt sensor
Fast Data Sampling up to 10 Hz
WaterTemperature measurement
Extremely long battery life with low-maintenance alkaline batteries
Real-time output/display capability; Fast Data Download
Long-term data logging to 2 GigaByte internal flash memory
ASCII serial data output via RS-232 or RS-485 (set at factory)
Built-in High Accuracy real-time clock with on/off power control
1.5-ton working strength mooring frame standard; options for 5-ton mooring frame
or frame with mooring line clamps
Optional pressure sensor or integrated conductivity, temperature, pressure sensor module (CTD) may be added
Choice of epoxy shallow-water (200m) or titanium deep-water (7000m) housings
Falmouth Scientific, Inc.
www.falmouth.com
SPECIFICATIONS
Sensors
Parameter Type Range Accuracy Resolution
Velocity Acoustic 0 to 600 cm/s ≤ 1%±0. 5 cm/s 0.01 cm/s
Direction 3 Axis Magnetometer 0 to 360° ±2° 0.01°
Tilt 2 Axis Accelerometer 0 to 30° 0.5° 0.01°
Temperature Semiconductor -3 to 40°C ≤0.1℃ ≤0.01°
Pressure (optional) Strain gauge 0 to 200 dBar ±0.1% 0.01%
Pressure (optional)
0 to 7000 dBar full scale full scale
Optional CTD
Range Accuracy Resolution Stability
Conductivity (mS/cm) 0 to 70 ±0.01 .001 ±0.0005 per month
Temperature (Celsius) -5 to 32° ITS-90 ±0.01° .001° ±0.0005° per month
0 to 200 dBar
Pressure (dBar) ±0.1% full scale 0.01% full scale ±0.01% per month
0 to 7000 dBar
Instrument
External Power: 8 to 32 VDC
Current Draw: 15 mA at 1 Hz sample rate; 80 mA at 10 Hz sample rate; 150 uAmp sleep
Battery Power: Alkaline 5 D Cell Welded Pack, 10 AHR
Internal Memory: 2.0GB Standard
Sample Rate: 10 Hz Maximum
Vector Averaging Period: User Selectable up to 59 Min:59 Sec
Real Time Clock: Programmable High Accuracy Sampling/Low-power Mode
Sampling Modes: Continuous, Interval, and Delayed Start (continuous or interval)
Clock Stability: +/- 2ppm (0-40 degrees C); +/-4ppm (-40 degrees C to +85 degrees C)
Input Channels: Two (2) 0-5V DC Input Channels with 12 bit A/D resolution available for external
sensor input, such as; Transmissometer, DO, OBS, etc.
(Regulated 12 VDC 1.5W provided to power external sensors)
Depth Rating/Physical Material: 200 Meter Epoxy Housing Standard, P/N: ACM-PLUS-200
7000 Meter Titanium Housing Optional, P/N: ACM-PLUS-7000
Mooring Frame: 1.5 Ton 316 Stainless Steel Mooring Frame (Standard, shown below left)
5 Ton 316 Stainless Steel Mooring Frame (Optional; see photo on page 1)
5 Ton 316 Stainless Steel with Mooring Line Clamps (Optional, shown below right)
Specifications Subject to Change without Notice
21Jan2014
Falmouth Scientific, Inc.
1400 Route 28A, PO Box 315, Cataumet, MA 02534-0315
fsi@falmouth.com Tel: 1-508-564-7640 Fax: 1-508-564-7643 www.falmouth.com
