MIDAS ECM – Electromagnetic Current Meter

The MIDAS ECM is a highly versatile point current meter, designed with durability and ease of deployment in mind.

Valeport’s latest electronics architecture allows multiple additional sensors, and a variety of communications options, making it one of the few multiparameter current meters that allows real time operations over several thousand metres of cable, as well autonomous deployments. A choice of titanium or acetal housing gives depth rating up to 5000m.

Sensors

Sensor	Type	Range	Accuracy	Resolution
Current	Valeport EM	0 – 5m/s	+/-1% reading	0.001m/s
Direction	Fluxgate	0 – 360°	+/-<1°	0.001°
Pressure	Piezo-Resistiv e	Up to 500Bar	+/-0.01%	0.001%
Temperature	PRT	-5 – +35°C	+/-0.005°C	0.002°C
Conductiv ity	Inductive Cell	0 – 80mS/cm	+/-0.01mS/cm	0.002mS/cm
Turbidity	Seapoint STM	0 – 2000FTU	+/-2%	0.001%

 

Data Acquisition
Continuous :	Regular output from all sensors at 1, 2, 4 or 8Hz.
Burst :	Regular sampling pattern, where instrument takes a number of readings, then sleeps for a defined time.
Conditional :	Instrument sleeps until a selected parameter reaches a set v alue.
Delay :	Instrument sleeps until predefined start time

Communications

The instrument will operate autonomously, with setup and data extraction performed by direct communications with PC before and after deployment. It also operates in real time, with a choice of communication protocols for a v ariety of cable lengths, all fitted as standard and selected by pin choice on the output connector :

Standard
RS232	Up to 200m cable, direct to serial port via USB adapter
RS485	Up to 1000m cable, addressable half duplex comms

Optional FSK 2 wire power & comms up to 6000m cable (cable dependent)
Baud Rate :	2400 – 115200 (FSK fixed at 19200, USB 460800)
Protocol :	8 data bits, 1 stop bit, No parity, No flow control

Memory

The MIDAS ECM is fitted with 16Mb solid-state non-v olatile FLASH memory. Total capacity depends on sampling mode; continuous & burst modes hav e a single time stamp at the start of the file, trip mode (profiling) stores a time stamp with each reading. Asingle line of current data uses 10bytes, with each additional parameter taking 2bytes and
a time stamp uses 7 bytes. The examples are for an instrument measuring speed, direction and CTD.

Continuous :	>520,000 data points
Profile :	>360,000 data points (>15 profiles to 5000m).

 

Electrical
Internal :	8x D cells, 1.5V alkaline or 3.6V lithium
External :	9 – 30V DC
Power :	1.7W (sampling), <1mW (sleeping)
Battery Life :	>100 hours operation (alkaline)
	>250 hours operation (lithium)
Connector :	SubConn MCBH10F

 

Physical
Materials :	Titanium or Acetal housing, polyurethane sensor components, stainless steel (316) cage
Depth Rating :	5000m (titanium), 500m (acetal)
Instrument Size :	150mmØ x 700mm long
Cage Size :	210mm Ø x 732mm long
Weight : (in cage)	20kg – Titanium 12kg – Acetal
Shipping :	130 x 37 x 32cm, 38kg – Titanium 130 x 37 x 32cm, 34kg – Acetal

Software

System is supplied with DataLog Express Windows based PC software, for instrument setup, data extraction and display.
DataLog Express is license free.

Ordering
0808007	MIDAS ECM Current Meter (Titanium)
0808008	MIDAS ECM Current Meter (Acetal)

measuring speed and direction the system is supplied with :

• Deployment cage.
• SubConn switch plug.
• 3m communications lead.
• USB adapter.
• DataLog x2 software, Manual, tool kit and transit case.

Options
04000565	Pressure sensor (specify range)
0400012	PRT Temperature sensor
0400011	Conductiv ity sensor
0400021	Turbidity sensor
0400002	16 Mbyte memory upgrade (max 64 Mbyte)
0400EA5	FSK modem adapter
TB0400FSK	Probe board set required for FSK operation

Read more :

• miniIPS – Intelligent Pressure Sensor;
• CTD and Multiparameter Instruments;
• Current Meters And Open Channel Meters;
• Model 803 ROV Electromagnetic Current Meter;
• Model 001 & 002 Open Channel Flow Meters