My datalogging systems are currently monitoring 1 USGS telemetry sensor and 5 sensors
located at my house in Redwood City California. The file name extensions corresponds
to the following sensor:
*.lc1 Long period (~14 seconds) homemade Lehman. This sensor is
oriented North-South.
*.lc2 Short period commercial vertical sensor. This sensor went offline
3/10/97 do to sensor failure. A new sensor was placed online 4/15/99
using this ID. This sensor was a L28 4.5HZ vertical short period unit.
Starting 3/2000 this channel ID is being used with a new test sensor.
The sensor is a vertical FBA. This channel is the integrated so the
output is velocity channel.
*.lc3 Long period (~60 seconds) homemade Shackleford-Gundersen
horizontal sensor based on the Sept. 1975 Scientific American
article. This sensor is oriented North-South and went online 11/95.
*.lc6 +-2G ADXL05 Strong Motion Accelerometer Sensor. Currently oriented
N-S. Went online 3/97 and offline 2/99.
*.lc8 Short period channel of *.lc3. Homemade Shackleford-Gundersen
horizontal sensor based on the Sept. 1975 Scientific American
article. This sensor is oriented North-South and went online 09/97.This
channel went offline 2/2001. This channel is now back online as of 4/2001.
*.lc9 GeoSpace HS-10-1 1 Hz vertical Geophone. This sensor went online 9/99.
3/2000 - Gain between the sensor and the A/D card = 250. This sensor is
currently offline.
*.lcs New PSN strong motion sensor. Online 11/99, offline 2/2000. This channel
is currently offline.
*.lcref Test Channel. Currently (11/2006) this channel is connected to a 4.5 Hz vertical
The following channels went online 6/1997
*.lcel +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A). This is
a horizontal channel oriented E-W. Starting 8/2001 this channel is
now named LCEL was LC4
*.lcnl +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A). This is
a horizontal channel oriented N-S. Starting 8/2001 this channel is
now named LCNL was LC5
*.lczl +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A), vertical
channel. Starting 8/2001 this channel is now named LCZL was LC7
The following channels went online 3/2000
*.lceh +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A) high gain
(G=200) channel. Oriented E-W. Full scale output = +-10 mg.
Starting 8/2001 this channel is now named LCEH was LCE.
*.lcnh +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A) high gain
(G=200) channel. Oriented N-S. Full scale output = +-10 mg.
Starting 8/2001 this channel is now named LCNH was LCN.
*.lczh +-2G Forced-Balance Accelerometer (Kinemetrics FBA-23A) high gain
(G=200) channel. Vertical Orientation. Full scale output = +-10 mg.
Starting 8/2001 this channel is now named LCZH was LCZ.
The following channels went online 2/2001 and offline 5/2002
*.rwn N-S component 4.5HZ Mark Products L-15B Geophone. Gain between the
A/D card and sensor = 250.
*.rwe E-W component 4.5HZ Mark Products L-15B Geophone. Gain between the
A/D card and sensor = 250.
*.rwz Vertical component 4.5HZ Mark Products L-15B Geophone. Gain between the
A/D card and sensor = 250.
The following channels went online 11/2001 and offline 02/2003
*.lcanh N-S component PSN-ACCEL accelerometer sensor board. High gain output.
*.lcaeh E-W component PSN-ACCEL accelerometer sensor board. High gain output.
*.lcazh Vertical component PSN-ACCEL accelerometer sensor board. High gain output.
The following channel went online 07/2003
*.lcsv1 Kinemetrics SV-1 5-Second Intermediate Period vertical sensor. Amplifier
gain = 200.
The following channels went online 06/2006
*.lctst VolksMeter raw channel. This sensor is similar to the Shackleford-Gundersen LC8
channel.
*.lctst1 VolksMeter integrated channel.
Channels in bold are currently online as of 11/2006.
Photo of the sensor.
Changes made 12/16/2002:
The Amplifier/Filter boards have been changed to my 4-Channel Amp/Filter
board. The low gain channels still have a gain of 1 and the high gain channels
200. All six channels have a 20 Hz 8-Pole low-pass filter and a 60 second
1-Pole high-pass filter.
Calibration:
The sensor was calibrated at Kinemetrics on 1/30/99. All recording channels
(*.LCEL, *.LCNL, *.LCZL) are set for a maximum output (+- 32768 A/D counts) of
+-2 g's. Each A/D channel's gain was measured to determine the actual
sensitivity.
Component Files Maximum Output Sensitivity Per Bit
E-W *.LCEL +- 1.996 g .06091 mg
N-S *.LCNL +- 2.004 g .06115 mg
Z *.LCZL +- 1.992 g .06079 mg
Filtering:
Each channel has the same high and low pass filtering.
High-Pass: 1-pole .072 Hz (13.8 second) Butterworth
Low-Pass: 6-pole 20 Hz Butterworth
High Gain Channels:
Starting 3/2000 I added 3 more channels from the FBA. These channels
(*.LCEH, *.LCNH and *LCZH) go through one of my 3 channel Amp/Filter
boards. Each channel has the following characteristics:
Gain: 200 High-Pass: 1-order .031 Hz (32 second) Low-Pass: 7 pole 20 Hz
Sensitivity: +- .01g full scale (+- 32768 A/D counts) or .304ug
(.2981 cm/sec/sec) per bit.
See note above regarding new filter settings.