Surveys and data


Instruments


Support to other department sections


Support Dr. Scient. thesis


Contribution to "Scientific infrastructure"


Obsolete, kept for reference


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Last update:
16 May 2014

CAVE INSTRUMENTATION


Click to visit book store.
Prof. Stein Erik Lauritzen book: "Grotter: Norges ukjente underverden".
Speleology is the science of exploration and study of all aspects of caves. At the Department of Earth Science, Prof. Stein-Erik Lauritzen conducts research in this area.

The instrumentation group's attempts to support this activity have had limited success, mainly due to constraints on time and personnel. The situation might change in the future, so these web pages are kept as reference.

On this page... (hide)

  1.   1.  PROJECTS
  2.   2.  CAVE INSTRUMENTATION ISSUES
    1.   2.1  Logger comparison
    2.   2.2  Drip rate counter
    3.   2.3  CO2
    4.   2.4  Water level
    5.   2.5  Draught meter
    6.   2.6  Radiolocation
    7.   2.7  Communication
    8.   2.8  Weather Station
    9.   2.9  Draught detection
  3.   3.  LINKS
    1.   3.1  Cave research
    2.   3.2  Tourist attractions
    3.   3.3  Instrumentation



1.  PROJECTS


Logger Logger unit. Click to visit project web page.

Water level & temperature recorder

Mapper Laser range finder & inclinometer
Project webpage Heatflux


2.  CAVE INSTRUMENTATION ISSUES


2.1  Logger comparison


Comparison of some Tiny Tag and Campbell loggers:

Parameter \ model Campbell CR-200 Campbell CR-800 Tiny Tag Plus Re-Ed'
Manufacturer Campbell Scientific Campbell Scientific Gemini
No. of channels 5 SE 6 SE or 3 Diff. 1 SE
Storage 32000 data points 2MByte 16000 data points
A/D resolution 13 bit - 8 bit
Input voltage range 0 - 2500 mV Selectable:
  • ± 5000 mV
  • ± 2500 mV
  • ± 250 mV
  • ± 25 mV
  • ± 7.5 mV
  • ± 2.5 mV
Selectable:
  • ± 0 - 2.5 V
  • ± 0 - 10 V
  • ± 0 - 25 V
Scan rate interval 1 Hz - ? 100 Hz - ? 1 Hz - 10 days
Excitation channels 2 (2.5 or 5 Vdc) 2 (with DAC; +/- 2 V range, 0.67 V resolution) 1 (100k output impedance), 159 ms duration;
sampling after 150 ms, 3.5 V pulse
Real-time clock - Yes -
Temperature range - -25 to 50 deg C -40 to 85 deg C
Current drain - Sleep mode: 0.6 mA
4.2 mA (1 Hz scan rate: without RS-232 data output)
Internal Lithium battery
Document links
Price NOK 6240
  • CR 800: NOK 12860
  • CR 850 (w/display and keyboard): NOK 15860
  • Tinytag Plus Re-Ed (8 bit) IP 68: SEK 1990
  • Tinytag Plus Re-Ed (8 bit) OEM: SEK 1490
Supplier IT-AS IT-AS Intab
Accessories needed

2.2  Drip rate counter


2.3  CO2


2.4  Water level


Digital

  • SDI-12 protocoll
  • RS-232, either bipolar volatge levels, or TTL
  • RS-485, multidrop
  • digital pulses

Analog

  • Voltage
  • Current 4-20 mA
MODEL DESCRIPTION
AANDERAA INSTRUMENTS WATER LEVEL SENSOR
CAMPBELL SCIENTIFIC Campbell Scientific

Water level sensor types

  • Sensor types (quoting from their web page)
    • Groundwater level, in deep observation wells: 6-wire resistive gages or vibrating wire pressure transducers
    • Groundwater level, in more shallow water applications: Piezometers, bubblers, or float and pulley systems
    • Surface water level, "measurements are often made in a vertical stand-pipe (stilling well) installed adjacent to a lake, river, or stream". "A float and pulley is often used, but pressure transducers, ultrasonic, and resistive tape sensors work well also ..."
  • Measurement range: 0.5 - 10 m
  • Accuracy: +/- 1 cm, or 0.4% of distance to target (whichever is greatest)
  • Operational accuracy: 1" (2.54 cm) typ
  • Resolution: 0.1 mm
  • Output: Serial ASCII, pulse train, SDI-12
UNIDATA WATER LEVEL SENSOR
  • Unidata, Australia
  • Mod 6541 Precision Water Level Instrument
  • Based on float system; as the water level changes the input shaft rotates. An optical encoder is mounted on the input shaft.
  • Measurement range: 0 - 65.5 m, or 0 - 13.1 m
  • Resolution: 1.0 mm, 0.2mm, 0.1 ft (depending on float pulley used)
  • Accuracy: Same as resolution
  • Output: "High speed serial signal UNIDATA HSIO standard". Options for SDI-12, 4-20 mA and dual HSIO channels.
  • Power: Internal battery pack, 1 year. Or external battery.
  • Based on differential pressure sensor, with venting tube to air. Also measures water temperature.
  • Operating range: 1, 2, 5, 10, 20 metres of water
  • Resolution: 0.05%, 0.05 mm @ 1 m range
  • Accuracy: +/- 0.2% full scale digital output (depth), +/- 0.3% full scale analog output
  • Power: 6 - 18 Vdv, 6 mA
  • Range: Three models, 0 - 0.5 m, 0 - 1.0 m, 0 - 2.0 m
  • Accuracy: 0.5 % of full scale reading
  • Output signal: 0 - 2.55 Vdc full scale
  • Power: 5 Vdc, 3.5 mA
STEVENS WATER MONITORING SYSTEM
  • http://www.stevenswater.com/
  • Their water level web page provide a description of sensor principles used: Pressure, Encoders/floats, Non-contact (ultrasonic), Capacitive. They have a broad range of sensors.
"PRESSURE BLADDER" WATER LEVEL SENSOR

Specifications:

  • Measurement range: 5 - 50 cm water

Design

UNIT CONVERSIONS

  • Source: Elfa.se
  • 1 PSI = 70.31 cm H2O = 6.895 kPa
  • 1 cm H2O = 0,01422 PSI = 0.09806 kPa
  • 1 kPa = 0.1450 PSI = 10.20 cm H2O

SENSORS

ITAS WATER LEVEL SENSOR

  • Supplier: ITAS
  • Model: MT_3
  • Range:
    • Price: NOK 3700

2.5  Draught meter


2.6  Radiolocation


2.7  Communication


Can it also be used for data communication?

2.8  Weather Station


Purchase from here:

2.9  Draught detection


SPORING VINDHASTIGET

HVORDAN KNUSE AMPULLEN
  • Elektromagnet
    Attach:elektromagnet.jpg Δ
    • Kraft: 16N @ 1mm / 1.1 N @ 15mm
      16 N -> tilsvarer kraft fra lodd på 1.6 kg.
    • Elfa P/N: 54-603-73
    • 24 V dc spole / 11 W
    • Forme akse som presser mot ampullen til en spiss slik at trykk pr. flateenhet blir større.
    • DC/DC-omformer som tar inn 1.5 V / 3 V spenning og konverterer til 24 Vdc, lagre energi i kondensator som så "avfyres" i spolen.
  • Fjær med utløser
    • Fjær som spennes, med elektronisk utløsermekanisme.
  • Motor m/gear som driver skrue
    • Skruen er spisset. Vi kan her sikkert få den kraften vi trenger.

ELEKTRONISK BRYTER

Det finnes mange komponenter som er effektive brytere, og som kan slippe mye strøm igjennom.
La oss si 15 A, 24 Vdc - bruker Power Mosfet - kanskje 0.3 ohm motstand over "bryteren" når den er på. Noen kan styres med 0 - 5 V puls. Tyristorer kan også vurderes.

SPØRSMÅL OM TIDSSTYRINGEN

  • Er det et bestemt klokkeslett som skal innstilles, eller er det nok å kunne velge x minutter frem i tid, fra man aktiverer enheten?

MEKANISK

  • Hva er max ønskelige mål?



3.  LINKS


3.1  Cave research


3.2  Tourist attractions


.. Stump Cross is the scientific work occurring in the cave .. Data loggers are currently in the cave measuring drip rates ..

3.3  Instrumentation


The electronic journal Speleonics is the official publication of the Communications & Electronics Section
  • Auriga is a Palm OS cave survey freeware.
  • Hydrolab Minisonde: Temperature, DO, Conductivity, and pH plus up to two additional sensors
Department of Earth Science
University of Bergen
N O R W A Y