Model QM-4.5-ADXL203 Single-Axis, Strong Motion, Accelerometer System.

Welcome to The Inexpensive Seismometer Project, an attempt reduce the cost and complexity of amateur seismic systems.

This page is about my project to build simpler and less expensive amateur short period seismometers by using microprocessors and other new chips, such as switched capacitor filters. Short period seismometers are useful for detecting and analyzing local seismic activity (within a few hundred miles or closer). 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 long period system.

December 2015 QM accelerometer system status: Now shipping ADXL203 sensor based systems worldwide!

The QM-ADXL203-20HZ strong-motion, single-board, single-channel accelerometer design:

• Sensor: ADXL103 single-axis 1.5g accelerometer chip with lower noise than ADXL105 or ADXL202.
• QM-ADXL203-20HZ low pass elliptic filter chip MAX4703 is set to bandpass 0-20 Hz.
• QM-ADXL203-20HZ board 16 bit adc resolves acceleration 0.07 mG over +/- 1.5 G range
• QM-ADXL203-20HZ rms noise level is about 20 adc units, or 1.5 mG.
• A diecast aluminum enclosure (Hammond 1590)is provided for EMF and thermal shielding.
• Accelerometer Low-pass filter: 8 pole Bessel filter lowpass cutoff set to 20 Hz.
• Accelerometer filter chip: MAX7403CPA 8th order, lowpass, Bessel, switched capacitor filter.
• Microprocessor: 8 bit, 4 mHz PIC14000 with 16 bit A/D, replace chip to upgrade software.
• A to D: PIC14000 integrated 16 bit adc covering a 0-4.95 volt range.
• Microprocessor software: burned into PIC14000, controls A to D, time integration, etc.
• Voltage regulator: micropower LP2950ACZ-5.0 with very low dropout voltage.
• Serial output rate is adjustable (by DIP switch) from 8 to 35 samples per second.
• Serial output 15' cable with DB9 female connector for PC COM port.
• Serial extension cables (DB9 M/F) up to 100' are usable for remote sensor locations.
• Serial output rate is 9600 baud, 8N0.
• Serial output ASCII records vary from -32767 to +32767, where 0 is zero velocity/acceleraton.
• Power is derived from the PC serial port, and the board turns on when connected.
• Power on board is single-supply @ 5 volts, current is less than 4 ma @ 5 volts.
• LED Power On indicator blinks at sampling rate.
• You download Amaseis (freeware) for data logging, helicorder display, data export, etc.
• You download AboutTime (optional/freeware) for time synchronization via Internet.
• You download RighTime (optional/free trial) if you need to adjust Win95/98 PC clock.
• You download WinQuake (optional/free trial) for seismic data analysis.

• You can pay by check, money order, credit card or PayPal. The QM-ADLX203 strong motion accelerometer is avalable in two versions: QM-ADXL203H-20HZ single axis, horizontal, digital accelerometer, or QM-ADXL203V-20HZ single axis, vertical, digitl accelerometer. There is a diecast aluminum enclosure around the circuit boardand accelerometer. To start recording, all you need is to download the Amaseis software and plug the QM-ADXL203-20HZ serial cable into your PC serial port.

  OPTIONS: Options include a longer additional serial (DB9 M/F) extension cable if your PC will be a long distance from the sensor. The QM-ADXL203-20HZ has a built-in serial cable that is 15 ft long. We have some serial extension cables that are 10 ft ($10), 25 ft ($20), 50 ft ($30), and 100 ft ($50) long.

  MAIL ORDERS: We are now buidling QM-ADXL203H-20HZ and QM-ADXL203V-20HZ strong motion seismometer that is ready to run with the free Amaseis computer software.

  PRICES
  ___Complete accelerometer unit in case for RF and thermal shielding:
  1 QM-ADXL203V-20HZ Assembled/tested, diecast enclosure, 15 ft cable, software and manual on CD @ $345
  1 QM-ADXL203H-20HZ Assembled/tested, diecast enclosure, 15 ft cable, software and manual on CD @ $345
  ___Shipping:
  1 Shipping within the US is by USPS Priority Mail is included in price
  1 Shipping worldwide by US Air Mail @ $65, but this does not include tracking.
  1 Shipping worldwide by UPS @ $160, including tracking.
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  To order, paypal to "Infiltec@gmail.com" or contact Infiltec for credit card processing or other payment options:
  

  Infiltec Seismometers
  108 South Delphine Avenue
  Waynesboro, VA 22980
  
  Phone: 540-943-2776
  Fax: 540-932-3025
  

  Email: Infiltec.

  CREDIT CARD/PAYPAL ORDERS: you can order by credit card (MV/VISA/AMEX) pr PayPal by printing out our Order Form(text) or

  AVAILABLITY: It generally takes about two weeks to build and test your system, after we receive your order.

  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.