Hilger & Watts
Atomic Bomb Test Ban
Earthquake Early Warning
Seismometers & geophones are
some of the sensor
types that I find interesting. The applications are
Classically seismometers have been used to record the ground
shaking as the result of earthquakes. By measuring the
time from the "P" wave to the slower waves the radial distance
between the sensor and epicenter can be calculated. The
magnitude and duration of the slow waves gives an indication
of the energy. This is the application that first got me
Geophones are used to look for reflections caused by changes
in density of sub surface layers after a surface explosion or
a tamper initially shakes the ground. These are
typically used in large arrays.
Outdoor intrusion detectors
geophones as well as other methods to detect ground vibrations
caused by moving men and machines. Knowing about the use
of seismometers for recording earthquakes and then
seeing this application reinforced my interest.
Machine Balancing & monitoring
Some industrial motors are connected to a system that can be
balanced so sensing the out of balance helps make the initial
In an industrial environment when a machine is breaking down
or is about to, it starts to shake and detecting the vibration
allows shutting the motor off before there's a catastrophic
Detecting Nuclear Blasts
As part of the Non Nuclear Proliferation treaty a need arose
to detect nuclear blasts and differentiate them from other
types of blasts. Seismometers are able to do that by the
wave form shape.
Note that the technology used for seismometers is very similar
to that used for pendulums
There are a number of
technologies used for vibration
. One of these is very similar if not
identical to the geophone. The difference may be in the
frequency range that's being monitored. Vibration
sensors typically are concerned with audio frequencies and
into the ultrasonic whereas geophones and seismometers are
looking at infrasound
Hilger & Watts
Label SG450, 157222, Made in England.
The Teledyne Geotech S13 Seismometer looks very similar and they
show up on eBay now and then.
Variable Oscillation Period Seismometer (see patent below) that
can be used vertically or horizontally. Permanent magnet
and coil of wire.
Watts Seismometer Open
Watts Seismometer Close Up
2 of 3 possible windings
Diameter 6.625", height to top
of handle under 15" (varies with leveling feet) 27.5 pounds.
Voltage Generator6 is a floating permenant magnet with a fixed
coil (20) in the gap. Three bottom spokes 8 and two top
spokes 10 locate the magnet so that it's free to move up and
down (as shown in the patent drawing, but there's a way to use
it on it's side).
Spring Lifting System
The arms (14) are firmly attached to the magnet by a central
rod. Four triangular leaf springs (19) their base ends
clamped to arms (14) and their pointed ends are linked
(18) to the pointed ends of the top springs (19).
There's a plate anchored to the frame (shown just above 26a)
which holds brackets at the base of two of the top springs
(19). One of these is shown in the upper left of the
drawing. There are two Allan head screws that clamp the
spring to the bracket (the upper left screw and another behind
it not shown). There are two pivot screws whose ends sit
on the plate (above 26a) shown as the single screw to the right
of the bracket. The central screw goes through a clearance
hole in the bracket and into a tapped hole in the plate.
These two screws have horizontal holes in the head so they can
be adjusted from the side.
Spring Lifting System - Not shown in patent drawing
other two top springs (19) are held by an identical pair of
brackets, but instead of being connected to the plate (above
26a) they are connected to a plate that's been cut out of the
first plate. An an are bolted to the top of the plate
(above 26a) and cantilevered out over the cut out section of
plate. In it's outer end there's a tapped hole.
The screw in that hole can be turned to cause the floating
plate to move and this changes the tension of the spring
system. The screw can be accessed by removing the large
headed screw that holds the cover over the clamping screw
(22). The highest dial setting that I can get to work in
the vertical position is "18" and here the spring lifting
system adjustment screw is backed out so that it's
cantilevered is almost touching the floating plate.
If the dial associated with the
period adjustment (knob at top left) is set to full CCW it
stops at about 23. But it's impossible using the spring
lifting system screw to center the magnet (6) in it's range of
travel. This might require using a pin to adjust the
other two screws or some other adjustment, or maybe it can't
be done. The resistor that caused critical damping when
the dial was at 15 is much too weak when the dial is at 18 and
the period is some number of seconds. It takes a number
of cycles of ringing until the mass stops.
If you have any documentation on how to use this Hilger
& Watts seismometer please let
The three coil termination pairs
have letters scratched in the phenolic. Although there
are positions for 6 output wires, on this unit only 4 are
used. The patent mentions that the damping needs
to be adjusted for the selected period. This unit
has two separate coils, C-D (1k5 Ohms) and E-F (7k6
Ohms). There is a brown jumper between D and E thus
presenting the full coil between C and F (White and
Yellow). Connector pins B & F go to a pair of
wires terminated with a 6k7 Ohm resistor that I choose for
The connector is marked in the center of the insulating block
148-CP and has 6 male pins. Threads for mating
shell are 0.864" O.D. mating insert OD less than 0.691"
O.D. with a single grove for keying.
The dial calibrated from 0 to 25 which should change the
period instead seems to move the mass up or down and when at
15 the rod in the height viewing dome is level with the center
fiducial mark. Moving this dial to either extreme
bottoms the mass.
The label on the outside "1NS" implies this was used in the
horizontal position. But when placed horizontally the
mass locks up. So it's really not working
correctly. There is probably something that needs to be
done to get proper operation when vertical, which is the
position I'd like to use.
These look similar to the sensors used in the GR-8 Sound
Patents by Willmore:
Variable Oscillation Period Seismometer, Patrick L. Willmore,
August 3, 1965, 367/185
3685011 Seismometer, Francis E.
Lehner (Cal Tech), Aug 15 1972, 367/182
; 73/654 -
ciol in magnet type with calibration pulse input, maybe 5
second period (adjustable).
3194060 Seismic Displacement Transducer, L.T. Greenwood
(NASA), Jul 13 1965, 73/654
; 367/179; 73/382R -
2074043 Seismograph, Louis Statbam (Std Oil), Mar 16, 1937,
; 310/15; 73/654 - cylindrical package, down
hole? permanent horseshoe magnets
2873103 Seismological Instruments, R.F. Hautly, Feb 10 1959,
; 73/514.14; 73/650 - torsional damped limited
frequency response reflecting mirror
1869828 Devices for Measuring and Recording Vibrations in
2487793 Object Controlling Electric Motor System, (Sperry
Gyro) - used as part of aircraft auto pilot
2542018 Compass, Ferrill (Sperry Corp), Jr. et al, Feb 10
1951, 33/360 ; 33/362; 33/363Q; 73/504.14 -
2552722 Electromagnetic Accelerometer, John G. King, May
15 1951, 73/514.12 ; 324/127; 33/DIG.5; 336/135;
336/30; 336/67; 336/92; 336/94; 340/870.35; 73/514.31-
magnet if bob of pendulum
2616681 Angular Velocity Responsive Apparatus, C.T. Morrow
(Sperry Corp), Nov 4 1952, - ref 2513340
2842752 Geophones, W.M. Jones (British Petrolum), Jly 8
; 267/160; 336/100; 336/136
2852769 Time Interval Multiplier, R.L. Plouffe (Navy), Sep
16 1958, 342/186
; 327/134; 327/172; 327/174;
Air deliverable seismic
B Henderson, Texas
Dec 5, 1972, - saw
patent number of a different seismometer on eBay.
The Quake Alarm is just a simple
brass rod pendulum whose lower end is in a triangular opening
in a brass block. The brass block can be moved in and
out by means of the adjusting screw on the front thus changing
the gap between the rod and block, i.e. the sensitivity.
BUT, this is not a P wave detector but rather a horizontal
motion detector, not what I was looking for.
This one is made by jds Products andis their model QA-2000.
At a prior house I had a similar looking unit that was a true
P wave (Wiki
detector to give earlier warning of a quake.
This is a P-wave (Wiki
detector that sounds a warning prior to the arrival of the S
(shear) wave that has the high energy. The p-wave is an
up-down motion that arrives before the S-wave, where the time
difference depends on the distanct to the epi center.
Not much warning if the quake is local, but a couple of
minutes for someone in San Francisco during the 1989 Loma
Prieta quake (Wiki
Atomic Bomb Test Ban
By using a high dynamic range and wide bandwidth ( 10 seconds to
10 Hz) seismograph the difference between an earthquake and an
explosion can be detected. The Vela Uniform project (Wiki
investigated how to do this. Keywords: Long Range Seismic
1784415 Electrical Recording Seismograph, H. Benioff (Carnegie),
Dec 9 1930, 340/870.16
; 310/15; 340/870.31; 340/870.44;
346/107.1; 346/65; 367/179; 367/182; 73/654
2933715 Seismic Device,Beuermann, Apr 1960,
2269453 Device for Detecting Displacements, E.L. Gayhart,
2348225 Magnetic Seismometer, O.S. Petty, May 1944 - oil
2576775 Seismometer System, F.D. Case (Diamond Inst), Nov
1951, - long period earthquake detection in small size
2683867 <See below>
2756406 Vibration Detector, G.S. Schurman (Calif. Research
Inst), July 1956, - Frequency Response vs. Geophone mass -
2788512 Low Frequenc Seismometer, W.J. Reichert (Shell),
April 9 1957,
2707776 Magnetron Type Seismometer, Cruzan (Phillips Petro),
May 1955 -
2683867 Parachuted Radio Seismic Transducer, J.O. Vann (not
assigned), July 13 1954, - for measuring polar ice
3225328 Transportable Seismograph, F Lecroart,
Low frequency oscillator with negligible resistance, Thompson Robert R
, Standard Oil Dev Co, Oct 26, 1937, 333/186, 323/354, 331/154, 323/344, 336/136, 336/41
- coil over magnet suspended by spring, very high Q
2111643 Seismometer, H. Salvatore (Western Geophysical Co), Mar
22 1938, - combine permanent magnets and coils - prospecting
2418953 Transducing System, R.W. Raitt
2519916 Inertial Electromagnetic Throat Microphone, D.W.
2470244 ELECTRICAL REPRODUCING STYLUS - for machine shop
2562983 Frequency Adjustable Seismic Wave Detector, D.H.
Clewell, Aug 7 1951, - oil prospecting
2643367 MAGNETOSTRICTION SEISMOMETER, (Phillips Petroleum Co)
2663088 Pendulum and Acceleration Compensation System, R.T.
Cloud (N. Am Geo)
2540796 VIBRATION TRANSLATOR, A.N Stanton
2671202 VIBRATION PICKUP, M.O. Petroff (Stewart-Warner), Mar 2
1954 - wheel balancing
2595067 INERTIA TYPE VIBRATORY PICKUP, J.A. Flint (Jeffrey
Mfg), Apr 1952
2659065 SEISMOMETER, R.L. Cordell (Stanolind Oil)
3066526 UNBALANCE DETECTION APPARATUS, H.R. Tear
(Stewart-Warner),- wheel balancing
3480808 POWER GENERATOR, F. Rieth (Packard-Bell) - probably
for TV remote
4740775 Automobile burglar alarm, R. Price,
4584569 Motion sensitive security system,
5323133 Method and apparatus for making
electrical connection with a movable member, - loudspeaker
The above patents were found by
looking for patents that are called by or call the Hilger
& Watts patent.
displacement vibrometer, Gulf
Research Development Co,
Sep 26, 1944,
------------------ Korean Conflict-----------
2533249 Seismic Detector, December 12, 1950, 310/25 ; 367/183;
2636160 Vertical Component Low Frequency Geophone, April 21,
----------------- Korean Conflict end -----------
2696592 Vib Pickup, December 7, 1954, 336/30 ; 335/285; 336/100;
336/136; 336/90; 73/654
2745085 Seismic Detector, May 8, 1956, 367/185 ; 310/14
2748370 Seismometer, May 29, 1956, 367/187 ; 174/77R; 267/160
2751573 App Chg Reas Freq, June 19, 1956, 367/183 ; 310/25
coil current changes reas freq
and can be done on whole string.
2753544 Seismic Detector, July 3, 1956, 367/182 ; 267/159;
2754435 Voltage Generating Vibratory Pickup Devices, T. Ongaro,
International R&D, July 10, 1956, 310/27 ; 367/183; 73/661
Machine Balancing or Monitoring
2756406 Vibration Detector, G.A. Schurman, California Research,
July 24, 1956, 367/184 ; 310/15
2764019 Vib Meas Dev, September 25, 1956, 73/654 ; 310/27;
rectify AC output and drive a
meter, no batteries machine monitor
2788510 Seismic Prospecting Apparatus, April 9, 1957, 367/86 ;
2788511 Frequency Seismometer, E.H. Marshall, Texas Inst, April
9, 1957, 367/187 ; 267/161, - oil exploration
2788512 Frequency Seismometer, April 9, 1957, 367/14
2788513 Cable, E.T. Howes, United Geophysical Corp, April 9,
1957, 367/180 ; 174/102SC; 174/106R; 174/27; 174/71R; 310/338;
2842752 Geophones, July 8, 1958, 367/182 ; 267/160; 336/100;
2923367 M App for Seismic sur, February 2, 1960, 367/34 ;
2933715 Geophones, April 19, 1960, 367/184 ; 310/15; 310/27;
2939079 METHOD OF CALIBRATING AN ELECTROMAGNETIC, May 31, 1960,
324/537 ; 324/202; 367/13
---------------- Vietnam Era ---------------
2980042 Method for Planting Seismic Detectors, B. McCollum,
April 18, 1961, 405/177 ; 111/199; 111/89; 343/719; 405/175;
405/183 - oil exploration
3020767 Linear Accelerometer, W.P. Kistler, KistlerInst Corp.,
February 13, 1962, 73/497 ; 267/160
feedback provices linear,
3057209 Seismic Vibration Pickup Means, K.F. Frank, Micro
Balancing Inc., October 9, 1962, 73/654 ; 336/40
dynamic balancing machine
3067404 Vibration Detector, A.B. Hilderbrandt, Jersey Prod Res,
December 4, 1962, 367/182 ; 310/15; 310/27; 73/652
3199072 Variable Oscillation Period Seismometer, August 3, 1965,
Hilger & Watts earthquake
3202847 Tunable Vibration Pickup Device, L.H. Erickson, August
24, 1965, 310/14 ; 310/15; 367/184; 73/654
alarm or balancing equipment,
3212057 Long Period Seismometer, F.E. Romberg, Texas Inst,
October 12, 1965, 367/184
portable horizontal period much
longer than equivalent pendulum, not as sensitive to tilt
(tolerates 0.5 deg).
aimed at nuclear detection
3241375 Transducer, R.M. Canzoneri, Consolidated Electrodynamics
Corp., August 24, 1965, 310/14 ; 310/15; 367/184; 73/654 -
strain gauge type, instrumentation, tolerates hi G
3451040 Spring Suspension for Low Frequency Geophone, W.P.
Johnson III, Mark Products, June 17, 1969, 367/183
3545286 Holder which is Displaceable Along one Axis, L.A.
Stenstrom, Philips, December 8, 1970, 248/604 ; 267/154;
267/160; 73/514.24; 73/654
3577184 Low Distortion Seismometer, W.O. McNeel, Geo Space
Corp., May 4, 1971, 525/342 ; 525/332.9; 525/333.1; 525/333.2;
525/359.1; 525/359.3; 525/359.5; 525/359.6; 525/361; 526/240
3582874 Electrodynamic Seismic Receiver, N.E. Fedoseenko, June
1, 1971, 206/6.1 ; 206/366
3582875 Geophone Device, S.H. Van Wambeck, June 1, 1971, 206/433
; 229/120.23; 229/120.27
3609674 Seismometer, S. Hansen, Hughes Aircraft Co., September
28, 1971, 65/135.7 ; 373/27; 65/136.4; 65/324; 65/327; 65/347;
65/356 - bubble movement is sensed and a PID feedback loop
provides wide bandwidth
---------------- Vietnam Era
Automatic method and apparatus for digitally indicating response
characteristics of geophones of a geophysical data acquisition
tuning a seismic transducer
4323994 Geophone Spring, J.M. Coogler, Geosource, April 6, 1982,
367/183 ; 267/158; 267/161; 367/187
4458344 Tapered Geophone SpringJ.M. Coogler, Geosource, July 3,
1984, 367/183 ; 267/161; 367/187
4623991 Delta Shaped Geophone Spring, F.A. Vitringa, Geosource,
November 18, 1986, 367/183 ; 267/161; 367/187
apparatus for testing geophones
5134593 Geophone Spring, R.M. Logan, Western Atlas Intl Inc.,
July 28, 1992, 367/187 ; 267/141.3; 367/183
Method and apparatus for testing components
Warning Alarm Patents
Class 340/ COMMUNICATIONS:
Motion detector suitable for detecting earthquakes and the like,
September 1987, 73/652
; 181/122; 340/580; 340/690;
Earthquake detector, May 1997, 73/654
200/61.45R; 340/690; 367/182 - all mechanical
Inertia switching device, acceleration responsive device and
method of Making Acceleration Responsive Device, November
- ball in cage switch
Earthquake detector, September 2000, 340/690
340/686.1 - long spring sensor/switch
||SAFETY DEVICE FOR
||Seismic tremor sensor
200/61.51; 74/89.14; 74/89.1
||Earthquake alarm system
200/61.49; 200/61.51; 340/669; 340/689
system with pendulum switch
116/303; 200/61.52; 33/391; 33/402; 340/690; 73/652
suitable for detecting earthquakes and the like
181/122; 340/580; 340/690; 367/182; 73/65
device (camera portrait or landscape)
||396/50 ; 396/287
||Motion and orientation
responsive device for seismic, intrusion, and tilt
200/61.45R; 340/690 like Quake Alarm
sensor and night light
340/321; 362/253; 362/806
200/61.45R; 200/61.51; 340/66
200/61.48; 200/61.51; 307/117; 340/690
181/122; 200/61.45R; 340/690; 367/182
340/540; 340/691.5; 340/693.5
|| ----- bad patent
||Earthquake detector and
200/61.45R; 340/601; 340/689
Earthquake-alarm device, October 2002, 340/601
200/61.52; 200/DIG.20; 340/689; 340/690; 340/691.1; 340/693.5;
702/15; 73/649 - like Quake Alarm
Earthquake detecting and warning device, February 28, 2006, 340/690
; 200/61.52; 73/579; 73/594; 73/649; 73/658 - inverted bowl
Earthquake Early Warning
They also has an Android app that uses the 3-axis g sensor
combined with the magnet compass when the phone is sitting
unused on the charger to report quakes.
This is better than the USB hardware which should be oriented
to magnetic North.
In the padded envelope you get:
* The seismometer,
* a couple of mounting wood screws
* a USB-A male to USB-B male cable
* one page of instructions.
On order is a pair of USB to CAT-5 LAN
adapters which should allow making a USB
extension cable over CAT-5 cable.
Also on order is a 100 foot CAT-5 LAN cable.
For $50 you can have your
own USB seismometer connected to the internet.
The sensor contains a 3-axis MEMS accelerometer and a USB
ONavi B 16 bit.
The QCNLive display of the 3 sensor outputs does auto scale,
so there should be some benefit from mounting the sensor
away from the house.
USB-CAT5 adapters & 100" CAT5 cable
This does not work. Why? Ans: handshake timing limits
cable length. But, an active USB extension cable does
work and these could be cascaded.
1. can the USB cable be extended say 100 feet to allow sensor
location far from the house?
2. does the software contain a circular memory so that the
data can be uploaded at a later time if there's a network
problem in real time?
3. Is there any intelligence in the sensor, i.e. a micro
4. Is there provision for adding different sensors, like those
on this page? Yes & No. There's a list of supported
sensors, but they are all USB based. There's not
provision for a 2-wire input type sensor like the Hilger-Watts
There are three programs that need to be downloaded and
Select “Add Project” (Lower Right).
Under “Project URL” type the following: qcn.stanford.edu/sensor
USB driver for the specific sensor you have
QCNLive - program running on your computer
File\Local Settings - Lat, Lon, Ele, etc.
Windows Firewall needs to have Boinc added as an exception.
Earthquake 25 Sep 2012 8:15 am Ukiah
The electronic equipment was swaying North-South and it
almost fell over.
Very strong shaking.
web page. M4.5