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The DrDAQ goes to sea (Liquid level measurement PART 3)

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The DrDAQ goes to sea (Liquid level measurement PART 3)

Postby Glovisol » Sun Oct 25, 2015 10:32 am

The work described in the previous Liquid Level Measurement post has been stimulated by the shortcomings of existing (electrical) systems form measuring tank levels in a boat. Existing systems use potentiometers and floaters and these items have a short lifetime when living in a water, or diesel fuel or waste environment.

With the three EXT. channels of the DrDAQ plus the scope channel it is possible to monitor and record as many critical on-board parameters and to read all of them at the same time on the on board PC display. An important feature is that all critical parameters can be equipped with alarms. A big shortcoming of Picolog is the small size display of the quantities monitored, but this problem can be easily overcome by using EXCEL to interrogate the DrDAQ with a Macro.
8. Excel display (Large).jpg
Large parameter display


The original Macro for the Excel file has been written by Martin Berriman. I have modified it by adding a section to read the alarm status. The Excel file is enclosed and starts working as soon as it finds an active Picolog on the same PC.


Installation of the pneumatic liquid level measuring system requires some care. The pipe going from the "T" junction to the tank should start in a high place and then go down to the tank pipe, which should be at the lowest point of the system: this arrangement will avoid the rise of moisture in the pipe.
Attachments
DrDAQ Metering 5.xls
This file reads all active parameters in Picolog
(36.5 KiB) Downloaded 52 times
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Re: The DrDAQ goes to sea (Liquid level measurement PART 3)

Postby alan » Mon Oct 26, 2015 4:07 pm

Nice - any photos of the setup?
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Re: The DrDAQ goes to sea (Liquid level measurement PART 3)

Postby Glovisol » Mon Oct 26, 2015 5:05 pm

Dear Alan,

I am busy building the system panel. This meant removing the original instrument panel and building (mahogany) a new one (boat is Sweden Yachts C-41). The system will not use the DrAQ (inputs are scarce) but the Picolog 1000 and the PC will show (with alarms):

-Water tank level.
-Diesel tank level.
-12 V Utility battery voltage.
-Utility Alternator alarm.
-12 V Motor battery voltage.
-Motor Alternator alarm.
-Engine coolant temperature.
-Engine oil alarm.
-Engine RPM (I still have to test if Picolog will measure 50 Hz, corresponding to 3,000 RPM, but I am optimistic).

The PC also has Garmin cartography installed and uses the Garmin Bluetooth GPS MOBILE10 for navigation.

Will share all details after it is up and running.

Ciao,

Gianfranco
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Re: The DrDAQ goes to sea (Liquid level measurement PART 3)

Postby Glovisol » Tue Oct 27, 2015 6:04 pm

Sorry, this now has become a Picolog 1000 design, after starting as a DrDAQ project.....However the system is now complete, tested and ready to be mounted in the boat. The display looks like this, only a few more alarms are to be added.
12. QOS Excel display.jpg
Large Excel display of all parameters



The front panel looks like this. The components to the left of the pumps control the battery charger and the alternators and do not concern the parameter display.
9. QOS instrument panel front.JPG
Metering panel, front


The general view of the metering module is shown below. Note the layout where care is taken in keeping the sensors in the topmost position.
10. Metering module general.JPG
Metering module, general view


The detail of the Metering module is self-explanatory and is shown below.
11. Metering module detail.JPG
Metering module details


Hope this work will be useful to other sailors!
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Re: The DrDAQ goes to sea (Liquid level measurement PART 3)

Postby Glovisol » Fri Oct 30, 2015 9:06 am

More images concerning the metering system......

In the lab the RPM shown is obtained by taking a squarewave from the Function Generator of the DrDAQ driven by a separate PC. In actual service the RPM signal will be taken fro the "W" terminal of the alternator with a suitable resistor divider.

12a. Amended QUOS Excel display.jpg
Amended Excel display



3c. System detail.JPG
Module detail showing non-return valve support system
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