Geophysics Department TU Clausthal

deutsch english Applied Geophysics : Seismics

Seismometer-Galvanometer Coupling

Applet    ( in separate window, ca. 345 x 435 Pixel )

The applet shows in separate windows
a schematic diagram of the coupling network, and
an interactive graphic display of normalized coupling parameters,
and allows
to set relevant seismometer and galvanometer parameters in a dialogue area
to adjust the coupling network in the graphic display.

( Background : see Seismometer-Galvanometer Documentaion, in separate window )

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- HowTo -

Applet Dialogue :
( Screenshot )

shows / hides a schematic diagram of the coupling network.

shows / hides a graphic display of normalized coupling parameters.

controls the parameter dialogue and
the parameter adjustment in the graphic display window.

NO INSTR disables the parameter dialogue and allows the adjustment of all normalized parameters in the graphic display.

USER PAR and KIRNOS enable the parameter dialogue and inhibit the adjustment of the normalized parameters in the graphic display ( q_σ only is adjustable ).

INF and HLP display
informations to the actual cursor position ( INF )
and / or
hints to actually possible mouse actions ( HLP )
in the graphic display window.

Parameter Dialogue :
( Screenshots )

Example USER PAR

The screeshot shows the min. set of parameters, i.e.
coil and damping resistances of both instruments, Rc_s / g and Rd_s / g.
If Rd is set,
the use of the instrument parameters CDR, α0 and α is disabled
or if these instrument parameters are set
the max. damping value α_max and the damping resistance Rd are calculated and displayed.

( If incompatible prameter values are input, an error message is displayed in the field ERR: )

Example KIRNOS

The instrument parameters are preset with
values of a Kirnos seismometer and galvanometer,
and the values α_max and Rd
are calculated from these parameters, including σ_max and σ ( depending on q_σ ).

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- Screenshots -
( Graphic display, parameters see dialogue examples above )

Color code :
red = seismometer, blue = galvanometer, magenta = Rd_g/Rd_s or Rd_s/Rd_g, cyan = q_&sigma

For given normalized parameters Rd_g/Rd_s, Rc_s/Rds and Rc_g/Rd_g
the quotients (Rc_s+Re_s) / Rd_s and (Rc_g+Re_g) / Rd_g, functions of q_σ, are displayed in the range 0 ... 1 for q_σ and both functions.

( Values of q_σ and of both functions outside this range are meaningless for the coupling problem,  Details see Seismometer-Galvanometer Documentation. )

The normalized coil resistances Rc_s/Rd_s and Rc_g/Rd_g are displayed as horizontal lines,
in red / blue, where the distance to the resp. functions, i.e. the normalized external resistances Re_s/Rd_s resp. Re_g/Rd_g, are  ≥ 0.

The range of q_σ, where both results Re_s/Rd_s and Re_g/Rd_g are  ≥ 0  is marked green,
denoting the range of q_σ, compatible with the given dampings, i.e. damping resistances.

In mode NO INSTR the normalized parameters can be adjusted at scales :
Rd_g/Rd_s or Rd_s/Rd_g  below,
Rc_s/Rd_s  left and
Rc_g/Rd_g  right to the display.
For USER PAR and KIRNOS these paramters
are set in the parameter dialogue of the applet.

The value of q_σ can be adjusted in all three modes at the scale above the display.

Parameter scales :
left mouse button -> drag,
right button ->  set value,
lower left edge :
left mouse button ->  scale = Rd_g/Rd_s,
right button ->  scale = Rd_s/Rd_g.

In a text area at the upper edge of the display window
the first line lists the values of the normalized parameters,
and below
the actual value of q_σ and the resulting normalized coupling resistances are displayed.

Example NO INSTR
( Parameter values : preset at start of the applet )

Example USER PAR
( Parameter values : preset at start of the applet )

Example KIRNOS
( Parameter values : preset selecting KIRNOS )

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- Download -

Class and html files for a local installation of the applet are available as a zip file and as a tar.gz file.

More applets at : the author's Homepage

Rev. 11-dec-2006

Comments to Fritz Keller
( ned gschempfd isch globd gnueg )

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