Please for better view visit: http://itp.nyu.edu/~bp432/blug/archives/2007/02/datasheet_report_on_tsunameter.html

For the purpose of this assignment I decided to investigate Tsunami sensors. Most Tsunami detection systems include many different components including the SBE 54 manufactured by Sea-Bird Electronics, Inc.

Plus the optional features:


Pressure Sensor

A pressure sensor measures the pressure, typically of gases or fluids. Pressure is an expression of the force required to stop a gas or fluid from expanding, and is usually stated in terms of force per unit area. A pressure sensor generates a signal related to the pressure imposed. Typically, such a signal is electrical, but it might also include additional means, such as optic signals, visual signals and/or auditory signals. Pressure sensors have particular utility for monitoring the pressure in a fluid network. As compared with flow sensors, pressure sensors often require less cost to achieve a similar result. Pressure sensors are often fabricated using thin membranes that flex under pressure. Some pressure sensors function in a binary manner, i.e., when pressure is applied to a pressure sensor, the sensor acts to complete or break an electical circuit. Some speed cameras use them.

Pressure in a fluid

To measure the pressure inside a fluid, imagine introducing a sensor in the form of a tiny evacuated cylinder, with a piston at one end supported by a spring.

Specifics of Paroscientific Digiquartz pressure transducer

For data sheets and more information please visit:


Watchdog Timer

A watchdog timer is a computer hardware timing device that triggers a system reset if the main program, due to some fault condition, such as a hang, neglects to regularly service the watchdog (writing a “service pulse” to it, also referred to as “patting the dog”). The intention is to bring the system back from the hung state into normal operation. Watchdog timers may be more complex, attempting to save debug information onto a persistent medium; i.e. information useful for debugging the problem that caused the fault.

TCXO - Temperature Compensated Crystal Oscillator

Temperature compensated crystal oscillators typically employ a thermistor network to generate a correction voltage which reduces the frequency variation over temperature. The correction voltage is usually applied to a varactor diode in the crystal circuit such that the crystal frequency may be varied by a small amount. Temperature compensated crystal oscillators are essentially crystal oscillators which are tuned over temperature by a network in such a manner as to compensate for the natural temperature drift of the uncompensated crystal oscillator.


An EEPROM (also called an E2PROM) or Electronically Erasable Programmable Read-Only Memory, is a non-volatile storage chip used in computers and other devices to store small amounts of volatile (configuration) data. When larger amounts of more static data are to be stored (such as in USB flash drives) other memory types like flash memory are more economical. Non-volatile memory, or non-volatile storage, is computer memory that can retain the stored information even when not powered.

FLASH Memory

Flash memory is a form of non-volatile computer memory that can be electrically erased and reprogrammed. It is a technology that is primarily used in memory cards. Unlike EEPROM, it is erased and programmed in blocks consisting of multiple locations (in early flash the entire chip had to be erased at once). Flash memory costs far less than EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed. Examples of applications include digital audio players, digital cameras and mobile phones.

Decibar - dbar

A metric unit of pressure equal to 0.1 bar or 10 kilopascals. One decibar equals 75.006 torr, or 1.450 pounds per square inch (lbf/in2 or psi). The decibar is often used to measure the pressure of seawater, because an increase of 1 decibar in pressure corresponds closely to an increase of 1 meter in depth.


psi, psia, psid, psig are traditional symbols for pressure units used in hydraulics and plumbing. psi is a symbol for pound per square inch (see above). psia means pound per square inch absolute, which is the total pressure including the pressure of the atmosphere. Absolute pressure is referenced against absolute zero pressure, or a complete vacuum. The units of absolute pressure are followed by an "a", such as psia.


Means part per million.

An idea of data received from similar sensors

This is another product manufactured by Sea-Bird, which is a SEAGAUGE Wave & Tide recorder. It gives a better idea of the size of the sensor/recorder and the data logging.


SBE 54 is part of a much larger system

Flash animated system: