product product

Reinforced Land Cased Geophone 28Hz

Reinforced Land Cased Geophone 28Hz(P/N: ST-20DX,28Hz) is an ideal choice for shallow seismic survey and it is mostly widely used in coalmine geological prospecting and exploration with the following features:

  • Good parameter consistency.
  • Firm mechanism structure.
  • Excellent sealability and stability.
  • Vertical geophone, horizontal geophone are available which are also suitable for three component applications.
  • Reinforced land case and spike are specially designed for rugged fields.
  • Assorted geohone connectors and geophone cable are available.
  • 3-year limited warranty on basic element exclusive of high voltage, lightening or physical abuse.
  • SM-4 structure 28Hz geophone(P/N: ST-28N) is also available.

We supply reinforced land cased geophone 28Hz coil, geophone element, geophone sensor, single geophone, geophone array and multi geophone string with KCK connector, KCL connector, 408 connector, Kooter connector, MP16 connector, Split spring connector and Mueller clip connector optional as the lead connector.  Geophone leader cable from O.D 4.6mm to O.D 7.8mm available.

Click here and download data sheet of 28hz geophones or contact us to get special discounts.

download Request A Quote

For any inquiries, please contact with our Marketing Team at or Supporting Team at


Reinforced Land Cased Geophone 28Hz Product Parameters


(Equivalent to SM-4,28hz)

ST-20DX 28hz

(Equivalent to GS-20DX,28hz)

Natural frequency ( Hz )28 ± 5%28±5%
Open circuit damping0.60.22
Damping with Shunt Resistor0.634 ± 5%0.552±5%
Open Circuit Intrinsic Voltage Sensitivity(V/m/s)31.039.0
Sensitivity with Shunt Resistor(V/m/s)29.5 ± 5%28.0±5%
Coil Resistance (ohms)385 ± 5%395±5%
Harmonic Distortion ( % )<0.2≤0.2
Typical Spurious Frequency ( Hz )≧300≥350
Moving Mass ( g )10.211.0
Max.coil excursion p-p (mm)1.61.5
Max.tilt angle20º20º
Element Diameter (mm)2625.4
Element Height (mm)3233.5
Element Weight (g)8087.0
Operating Temperature(℃)-40℃ to + 100℃–45℃ to + 100℃
Warranty Period3 years3 years
● All parameters specified herein are rated at a temperature 20℃±2℃.
● 3-year limited warranty on basic element exclusive of high voltage, lightening or physical abuse.


– Other type of geophones are also available: SM-4 Equivalent, SM-6 Equivalent, SM-24 Equivalent, SG10 Equivalent, GS-20DX Equivalent, GS-32CT Equivalent, GS ONE Equivalent, 1Hz, 2Hz, 2.5Hz, 3Hz, 4Hz, 4.5Hz, 5Hz,8Hz, 10Hz, 14Hz, 15Hz, 28Hz, 30Hz, 38Hz, 40Hz, 60Hz,80Hz and 100Hz.

  • Home
  • Contact Us
  • Top
  • toptop