Welcome to The Inexpensive Seismometer Project,
an attempt reduce the cost and complexity of amateur
This page is about my project to build simpler and less expensive amateur long-period seismometers by using microprocessors and other new chips, such as switched capacitor filters. Long-period seismometers are useful for detecting and analyzing distant teleseismic activity (worldwide). For more general information on other types of seismometers and links to web resources, see my main seismometer page. Click here for information on my short period system.
Current Long Period Seismometer Electronics Status:
The latest QM-1.0 long-period processor improvements include:
See for latest updates to this page.
Here is the circuit schematic. Note that my short period QM-4.5 seismometer printed circuit board is identical to the QM-1.0 board except for passive component value changes to reduce the lowpass filtering to 4.5 Hz. The QM-4.5 is designed to work with a 4.5 Hz Mark Products geophone.
Here is my latest short-period, single-board, single-channel seismometer design :
OPTIONAL EXTENSION CABLE: You may want to consider a serial (DB9 M/F) extension cable if your PC is a long way from your Lehman/geophone. The QM-1.0 has a built-in serial cable that is about 10 ft long, and a cable to the pickup coil that is about 6 ft long. I have some serial extension cables that are 10 ft to 100 ft long.
__ASSEMBLED long-period seismometer electronics in diecast aluminum case (for use with AS1 or Lehman Sensors)
1 QM-1.0-3704 assembled/tested pcb, in case, 15 ft serial cable, coil, magnet @ $295
__KIT long-period seismometer electronics with diecast aluminum case (for use with AS1 or Lehman Sensors)
1 KQM-1.0-3704 bare pcb, components, case, 10 ft cable, coil, magnet @ $195
1 QM-370-4 General Tool horseshoe alnico magnet, 22lb/9.97kg pull, fits 9k ohm coil @ $25
1 QM-02712 15ft DB9 M/F Extension Cable @ $10
1 QM-09452 25ft DB9 M/F Extension Cable @ $20
1 QM-09453 50ft DB9 M/F Extension Cable @ $30
1 QM-17612 100ft DB9 M/F Extension Cable @ $50
1 Shipping within the US by USPS Priority Mail with insurance @ $25
1 Shipping outside the US by USPS Global Priority Mail with insurance @ $45
Print out our Order Form (text)
and fill out your order and calculate the cost.
Mail a check or money order payable to Infiltec to:
Infiltec Seismometers 108 South Delphine Avenue Waynesboro, VA 22980 phone: 540-943-2776 fax: 540-932-3025email: Infiltec.
FAX CREDIT CARD/PAYPAL ORDERS: you can order by credit card (MV/VISA/AMEX) by printing out our Order Form (text) and faxing it back to me. We do not charge your card before we ship.
PAYPAL ORDERS: (for orders shipping within the US only)
AVAILABLITY: It generally takes about two weeks to build and test your system, after I receive your order. You do not need to make a PayPal payment before I inform you that I am ready to ship your system.
WARRANTY: Your money back if you are not satisfied for any reason. Just return the system in reasonable shape for a full refund. If the system is defective, please ship it back for a no-charge repair. If you build a kit and it does not work properly, we will fix it for $25 plus shipping if you return it to us.
TUNE UP: Any time I make improvements to the microprocessor software and/or circuit, you can return the board for these upgrades for $30.
This page copyright © 2001-2015 by Infiltec Inc., all rights reserved. It was last updated on September 30, 2015.