DIY Radar.. tip?

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

 

[Spehro Pefhany]

On 10 Oct 2004 15:59:44 GMT, the renowned
pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Why don't you just buy a proper approved instrument from a competent
manufacturer such as Rosemount (shop around)? You're only looking at
maybe EUR1000, depending on manufacturer and accuracy.

Typically this stuff operates at around 10GHz and has a whack of EMC
and safety agency approvals.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[James Meyer]

On 10 Oct 2004 15:59:44 GMT, pbdelete@spamnuke.ludd.luthdelete.se.invalid wroth:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

If I had those requirements, I would go down to my local Home Depot or
builder's supply and buy a sonic tapemeasure. They're cheap and reliable.

Jim

 

[Fred Bloggs]

pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Forget it. Put a run-time meter on your oil pump control.

 

[Dev Cloete]

Try using a ultrasonic sender and receiver (+/-48Khz) mounted on a veroboard
and aim it at the oil surface). When you apply a signal to the sender and
measure the return signal fom the oil level on a Oscilloscope you will find
the phase between Tx & Rx signal varies with the oil level variation. Using
a phase comparator & logic circuit with it, you can measure the level very
accurately (Especialy in a tank which are stationary) Waves on the surface
will screw the signal around too much for accurate measurement.
Dev
<pbdelete@spamnuke.ludd.luthdelete.se.invalid> wrote in message
news:41695c70$0$174$cc7c7865@news.luth.se...

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

 

[YD]

On 10 Oct 2004 15:59:44 GMT,
pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Off the top of my pointy head: Endress+Hauser, Foxboro, Yokogawa.
Though in this case I'd rather go with ultrasonic rather than
microwave.

- YD.

--
Remove HAT if replying by mail.

 

[Dbowey]

YD posted:

<< On 10 Oct 2004 15:59:44 GMT,
pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Off the top of my pointy head: Endress+Hauser, Foxboro, Yokogawa.
Though in this case I'd rather go with ultrasonic rather than
microwave.
I agree. And I believe others have implied the same. The problem with MW in
this application, is it's fast propagation time. As I recall, a "radar mile"
is about 12.4us; the time it takes for the pulse to travel out one mile and be
returned.

How tall is your tank, and what is the highest and lowest content height?
Within that range of feet, do you believe you can send the signal, receive the
"echo" and process to an accurate result? Not very easily, but you are the one
who must decide that. If you try it, I suggest you try a Continuous Wave
method with a good directional coupler, at somewhere higher than 10 GHz.

On the other-hand, ten years (or so...) ago, I read specs on IC's that are a
complete ultrasonic transceiver that should be very easy to use in your
application. I believe they were used in camera auto-focus devices and it was
very simple to correlate time and distance accurately. I bet current, similar,
ICs are even better.

Don

 

[Spehro Pefhany]

On 11 Oct 2004 00:55:36 GMT, the renowned dbowey@aol.com (Dbowey)
wrote:

YD posted:

On 10 Oct 2004 15:59:44 GMT,
pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:


Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Off the top of my pointy head: Endress+Hauser, Foxboro, Yokogawa.
Though in this case I'd rather go with ultrasonic rather than
microwave.


I agree. And I believe others have implied the same. The problem with MW in
this application, is it's fast propagation time. As I recall, a "radar mile"
is about 12.4us; the time it takes for the pulse to travel out one mile and be
returned.

How tall is your tank, and what is the highest and lowest content height?
Within that range of feet, do you believe you can send the signal, receive the
"echo" and process to an accurate result? Not very easily, but you are the one
who must decide that. If you try it, I suggest you try a Continuous Wave
method with a good directional coupler, at somewhere higher than 10 GHz.

On the other-hand, ten years (or so...) ago, I read specs on IC's that are a
complete ultrasonic transceiver that should be very easy to use in your
application. I believe they were used in camera auto-focus devices and it was
very simple to correlate time and distance accurately. I bet current, similar,
ICs are even better.

Don

Good commercial rader level sensors (used in petrochemical tanks, for
one big application) are in the 1-5mm accuracy/resolution range. And
they don't depend on the varying speed of sound in layered vapor-laden
air, at various temperatures, and perhaps with a temperature gradient.
They can also go through a fiberglass lid - no exposure of the sensor
is required.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Winfield Hill]

Spehro Pefhany wrote...

Good commercial rader level sensors (used in petrochemical tanks, for
one big application) are in the 1-5mm accuracy/resolution range. And
they don't depend on the varying speed of sound in layered vapor-laden
air, at various temperatures, and perhaps with a temperature gradient.
They can also go through a fiberglass lid - no exposure of the sensor
is required.

Examples, links? :&gt


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[Dbowey]

Spehro posted:

<< On 10 Oct 2004 18:31:13 -0700, the renowned Winfield Hill
<Winfield_member@newsguy.com> wrote:

Spehro Pefhany wrote...

Good commercial rader level sensors (used in petrochemical tanks, for
one big application) are in the 1-5mm accuracy/resolution range. And
they don't depend on the varying speed of sound in layered vapor-laden
air, at various temperatures, and perhaps with a temperature gradient.
They can also go through a fiberglass lid - no exposure of the sensor
is required.

Examples, links? :&gt

Sure:-

http://www.rosemount.com/document/pds/4024_00n.pdf
http://www.solartronmobrey.com/products/level/continuous/mrl700.php
http://www.psm-sensors.co.uk/irtdataFMCW.htm
http://www.ktekcorp.com/portal/Portals/57ad7180-c5e7-49f5-b282-c6475cdb7ee
7/pressreleases/K-Tek%20Radar%20Story%20Layout%20w%20Logo.pdf
Super cool goodies with good specs.

Don

 

[Paul Hovnanian P.E.]

pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

Accuracy required? User interface requirements? Other environmental
considerations?

Without further information, I'd recommend the simplest and cheapest
level sensing system. A dipstick.

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Programmers don't die, they just GOSUB without RETURN.

 

[Dbowey]

But now try to build one. This *was* a request for a DIY project.

Don

 

[Spehro Pefhany]

On 11 Oct 2004 03:09:08 GMT, the renowned dbowey@aol.com (Dbowey)
wrote:

But now try to build one. This *was* a request for a DIY project.

Don

Ok, here's a 10.525GHz (X-band) Gunn diode transceiver with 50MHz of
varactor tuning.

http://www.shfmicro.com/10ghz.pdf

Anyone want to take this further?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Spehro Pefhany]

On Sun, 10 Oct 2004 21:58:08 -0700, the renowned John Miles
<jmiles@pop.removethistomailme.net> wrote:

In article <c00km0hu18uojdgku1ulv6618q9mhfeuph@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat says...
On 11 Oct 2004 03:09:08 GMT, the renowned dbowey@aol.com (Dbowey)
wrote:

But now try to build one. This *was* a request for a DIY project.

Don

Ok, here's a 10.525GHz (X-band) Gunn diode transceiver with 50MHz of
varactor tuning.

http://www.shfmicro.com/10ghz.pdf

Anyone want to take this further?


Best regards,
Spehro Pefhany


They can be tuned a lot farther than +/- 50 MHz if you can swing the
varactor across its full 0-20V (or so) range.

I've often wondered about the kind of resolution you could get from a
chirp radar made with those puppies. I still have a couple of 100 mW
parts around here, so maybe one of these days....
-- jm

Just the proper equipment to test it is a bit on the pricey side:

http://www.metrictest.com/product_info.jsp?mfgmdl=ADV%20R3182-20-27-29(D)

Probably John Larkin has a few of these laying around..

These things interact with some of the nastiest non-medical
regulations in virtually every country- they are intentional radiators
and they have intrinsic safety as well as health and safety issues. In
the country the OP seems to be posting from (Sweden) the manual of one
24GHz model says that they are illegal unless installed in a metal
tank. Still, they look like they'd be a ton of fun to fool around
with.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:

On 10 Oct 2004 18:31:13 -0700, the renowned Winfield Hill
Winfield_member@newsguy.com> wrote:

Spehro Pefhany wrote...

Good commercial rader level sensors (used in petrochemical tanks, for
one big application) are in the 1-5mm accuracy/resolution range. And
they don't depend on the varying speed of sound in layered vapor-laden
air, at various temperatures, and perhaps with a temperature gradient.
They can also go through a fiberglass lid - no exposure of the sensor
is required.

Examples, links? :&gt

Sure:-

http://www.rosemount.com/document/pds/4024_00n.pdf
http://www.solartronmobrey.com/products/level/continuous/mrl700.php
http://www.psm-sensors.co.uk/irtdataFMCW.htm
http://www.ktekcorp.com/portal/Portals/57ad7180-c5e7-49f5-b282-c6475cdb7ee7/pressreleases/K-Tek%20Radar%20Story%20Layout%20w%20Logo.pdf

Any ideas what these costs roughly?
Or what an app with the chip mentioned later in this thread would end up?

The tank is approx 1.5 diameter circular. And maybe some meters length. But
the important is the 1.5 length as the rest is simple trigonometry. The outdoor
temperatures here are usually -10 to 30 celsius. And -25 to 40 on the extreme.
"medium" humidity. The tank is approx .5 meters underground. So that stabelizes
conditions further. I wonder wheather penetration of glassfibre will succed
with precision not affected to much. Centimeter precision is enough.
As for EM interference, I don't think that's an issue because it will likely
need way less power than a 802.11b wlan device and be underground in soil that
is full with water.

I've thought a simple way to do it would be to cause some slight RFI noise by
a high dI/dt generation through a squarewave pulse possible reduced through a
capacitor or coil. And then have a capacitor wich is charged between the
positive flank of transmission. And the change of input. The charge should
be in relation to the timedelay (distance). And measured through voltage over
it with a ADC.

-----\ (mindstorm schematic
|
Pulse--Mosfet
| /
Resistor /
|___________ RF-out
|
Capacitor \
| \
------/

And then something to receive it.

| /
| /
Mosfet------ RF-in
| \
| \

Haven't figured howto put them together really yet

Any logic chips would be way to slow, althought I know scsi-sync and
scsi-ultra160 uses the cable as a fifo , so maybe it's feasable (5 ns/m).

 

[Rene Tschaggelar]

pbdelete@spamnuke.ludd.luthdelete.se.invalid wrote:

Any good links or tip on diy radar construction?

I'm mostly looking into measuring oil level in a tank of glasfiber. By
attaching such unit on the top.

I once saw a contruction where they had a steel rope and they used this
as waveguide for a somewhat lower frequency. Where this rope/wire was
immersed, it had different properties.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Scott Stephens]

Rich Grise wrote:

On Monday 11 October 2004 05:01 am,
pbdelete@spamnuke.ludd.luthdelete.se.invalid did deign to grace us with the
following:

The tank is approx 1.5 diameter circular. And maybe some meters length.
But the important is the 1.5 length as the rest is simple trigonometry.
The outdoor temperatures here are usually -10 to 30 celsius. And -25 to 40
on the extreme. "medium" humidity. The tank is approx .5 meters
underground. So that stabelizes conditions further. I wonder wheather
penetration of glassfibre will succed with precision not affected to much.
Centimeter precision is enough. As for EM interference, I don't think
that's an issue because it will likely need way less power than a 802.11b
wlan device and be underground in soil that is full with water.


...
Take two pieces of copper pipe, one that fits inside the other with some
gap, like a coax cable, but with a thick center conductor. Minimize the
gap, since it's going to be a capacitor. Mount it vertically in the tank,
and just monitor the capacitance. You'll have to calibrate it, of course.
(your stuff has a different dielectric constant than air, probably.)

Good Luck!
Rich

If you pulse or chirp radar down the 'leaky' waveguide it works real
good too!

--
Scott

**********************************

DIY Piezo-Gyro, PCB Drill Bot & More Soon!

http://home.comcast.net/~scottxs/

Those who sow excuses shall reap excuses

**********************************

 

[Rich Grise]

On Monday 11 October 2004 02:06 pm, Scott Stephens did deign to grace us
with the following:

Rich Grise wrote:
...
Take two pieces of copper pipe, one that fits inside the other with some
gap, like a coax cable, but with a thick center conductor. Minimize the
gap, since it's going to be a capacitor. Mount it vertically in the tank,
and just monitor the capacitance. You'll have to calibrate it, of course.
(your stuff has a different dielectric constant than air, probably.)

Good Luck!
Rich


If you pulse or chirp radar down the 'leaky' waveguide it works real
good too!

Actually, the two concentric pipes are just a capacitor. You run it at

normal RLC meter frequencies - in fact, you could use an RLC meter,
as long as it can resolve fractional pf - I don't know how many it
would be, but the formulas are out there. When I was in the USAF,
on the way to/from the flight line I'd hear guys from the engine
shop talking about the fuel quantity indicator and picofarads in
the same breath. And I saw a thing that looked very much like a
tube, and I'm pretty sure it wasn't a float. ;-)

Hey, how about a float, and "full" and "empty" switches?
Or "Full", "Buy Oil Now" and "Freeze Tonight" switches? ;-)

Cheers!
Rich

 

[Mac]

On Sun, 10 Oct 2004 21:58:08 -0700, John Miles wrote:

In article <c00km0hu18uojdgku1ulv6618q9mhfeuph@4ax.com>,
speffSNIP@interlogDOTyou.knowwhat says...
On 11 Oct 2004 03:09:08 GMT, the renowned dbowey@aol.com (Dbowey)
wrote:

But now try to build one. This *was* a request for a DIY project.

Don

Ok, here's a 10.525GHz (X-band) Gunn diode transceiver with 50MHz of
varactor tuning.

http://www.shfmicro.com/10ghz.pdf

Anyone want to take this further?


Best regards,
Spehro Pefhany


They can be tuned a lot farther than +/- 50 MHz if you can swing the
varactor across its full 0-20V (or so) range.

I've often wondered about the kind of resolution you could get from a
chirp radar made with those puppies.

As stated elsewhere, there is an equation:

R = C/(2 * BW)

where R is resolution, C is the speed of light, and BW is the bandwidth,
in Hz. So 50 MHz of BW corresponds to 3 M resolution. If you can get more
than 50 MHz, you can get proportionally better resolution.

I still have a couple of 100 mW
parts around here, so maybe one of these days....

Keep us advised!

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

--Mac

 

[Spehro Pefhany]

On 10 Oct 2004 18:31:13 -0700, the renowned Winfield Hill
<Winfield_member@newsguy.com> wrote:

Spehro Pefhany wrote...

Good commercial rader level sensors (used in petrochemical tanks, for
one big application) are in the 1-5mm accuracy/resolution range. And
they don't depend on the varying speed of sound in layered vapor-laden
air, at various temperatures, and perhaps with a temperature gradient.
They can also go through a fiberglass lid - no exposure of the sensor
is required.

Examples, links? :&gt

Sure:-

http://www.rosemount.com/document/pds/4024_00n.pdf
http://www.solartronmobrey.com/products/level/continuous/mrl700.php
http://www.psm-sensors.co.uk/irtdataFMCW.htm
http://www.ktekcorp.com/portal/Portals/57ad7180-c5e7-49f5-b282-c6475cdb7ee7/pressreleases/K-Tek%20Radar%20Story%20Layout%20w%20Logo.pdf



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com