What is a Tide Gauge?
A tide gauge is an instrument used to measure the changes in water level with respect to a vertical datum. Also referred to as a marigraph or sea-level recorder, this device is mainly used for hydrographic surveying purposes. It records the variations in the sea level during high tides and low tides.
What Are the Uses of a Tide Gauge?
A tide gauge is mainly used for hydrographic surveying purposes. It helps measure the changes in sea level with respect to a vertical datum, thus recording the variations in the sea level during high tides and low tides. It is also used for other research purposes related to oceanography, meteorology, and coastal engineering.
Types of Tide Gauges
Tide gauges are classified into two main types as follows :
Non-recording type tide gauges
Recording type tide gauges
Non-recording type tide gauges
What are Non-recording Type Tide Gauges?
Non-recording type tide gauges are devices used to measure the rise and fall of tides in the sea. They require an observer to manually take readings from time to time and record them.
Types of Non-recording Tide Gauges
Non-recording tide gauges are classified into three main types: staff gauge, weight gauge, and float gauge.
Staff Gauge
A staff gauge is a type of non-recording tide gauge that uses a vertical staff with markings to measure the rise and fall of the tides. The staff is fixed in the ground and is fitted with a scale, allowing the observer to measure the height of the tides.
Weight Gauge
Weight gauges are non-recording tide gauges that use a weighted float to measure the rise and fall of the tides. The float is attached to the sea bed and is fitted with a weight, allowing the observer to measure the height of the tides.
Float Gauge
Float gauges are non-recording tide gauges that use an empty float to measure the rise and fall of the tides. The float is attached to the sea bed and is filled with seawater, allowing the observer to measure the height of the tides.
1. Staff gauge
WHAT IS A STAFF GAUGE?
A staff gauge is a simple type of tide gauge used to measure the water level. It is a vertical board with a width of 150 to 250 mm and a thickness of 100 mm. Staff gauges come in various heights, and the appropriate height is selected based on the conditions. Each staff gauge is graduated with a least count of 5 to 10 cm.
HOW TO USE A STAFF GAUGE?
Using a staff gauge is relatively straightforward. First, the elevation of the point where the staff gauge is to be used should be determined. If the elevation is unknown, it can be measured using a leveling instrument. Then, the staff gauge should be positioned vertically at that point. Finally, the variations in water level can be observed from a distance and noted manually.
2. Float gauge
What is a Float Gauge?
A float gauge is a type of tide gauge that uses a wooden box with a square section of 300 mm x 300 mm. Inside the box is a float attached to a graduated vertical rod. The bottom of the box contains a series of holes that allow water to enter, which then lifts the float. The readings are taken by looking at the graduated rod through a slit window.
Why is a Float Gauge Preferred?
Float gauges are preferred over staff gauges because they are easier to read during high intensity tides or when there are large variations in water level. The float gauge is more accurate and reliable than the staff gauge, making it the preferred choice for measuring water levels.
3. Weight gauge
What is a Weight Gauge?
A weight gauge is a device used to measure the weight of an object or material. It is available in two types – chain gauge and wire gauge.
Chain Gauge
A chain gauge consists of a horizontal graduated scale and a chain attached with weight. The chain is arranged alongside the graduated scale and passes over a pulley. The gauge is mounted on a support of known elevation and the weight is lowered until it touches the water surface. The reading is then observed on the graduated scale with respect to the index mark provided on the chain.
Wire Gauge
Wire gauges are typically used to measure the diameter, cross-sectional area, and the shape of a wire. It consists of a graduated scale and a wire attached with a weight. The wire is arranged alongside the graduated scale and passes over a pulley. The gauge is mounted on a support of known elevation and the weight is lowered until it touches the water surface. The reading is then observed on the graduated scale with respect to the index mark provided on the wire.
What is Wire Gauge?
Wire gauge is a type of weight gauge that uses a graduated reel of cable or wire instead of a chain and graduated scale. This type of weight gauge also includes a pulley for the movement of the wire, which allows the reader to take measurements from the graduated reel. This type of weight gauge is used for precision measurements and can be found in various industries.
How Does Wire Gauge Work?
Wire gauge works by winding a graduated reel of cable or wire around a pulley so that the reader can take measurements from the graduated reel. The pulley allows the wire to move, which allows the reader to take precise measurements. The measurements can then be used to determine the weight of an object or the size of an object.
Benefits of Using Wire Gauge
Wire gauge is a highly precise tool for measuring weight and size. It is used in a variety of industries, including automotive, aerospace, and medical. This type of weight gauge is also highly accurate, which means that measurements taken using it are more reliable. Additionally, wire gauge is easy to use, making it a great tool for those who need precise measurements in their work.
Recording Type Tide Gauges
What Are Recording Type Tide Gauges?
Recording type tide gauges are automated instruments used to measure the variations in water levels over time. Also known as self-registering tide gauges, these devices are equipped with a float connected to a wire which is passed over a wheel. The wire is held in constant tension with the help of a counterweight or other suitable arrangement, while the float is shielded from wind and wave action.
Components of Recording Type Tide Gauge
Recording type tide gauges typically contain the same components. These include a float, a wire, a wheel, and a counterweight or other suitable arrangement to maintain the wire’s tension. The float acts as a measurement device and is protected from external forces that could affect the water level readings. The wheel is used to record the float’s movement, while the counterweight ensures that the wire remains taut.
Benefits of Recording Type Tide Gauge
Recording type tide gauges are advantageous for measuring water levels in various ways. These devices are able to provide accurate and reliable readings over long periods of time with minimal maintenance. Additionally, the float and the wire arrangement protect the gauge from external forces that could affect the readings, making it an ideal choice for recording water levels in challenging environments.
Paragraph 1:
Float Displacement Triggers Change in Water Level
When the water level changes, the float displaces and this triggers a movement that is transferred to the wheel. This wheel then reduces the scale of reading by using some gear system.
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Pencil Traces Curve on Graph Paper
The wheel movement is then conveyed to a pencil which traces a curve on graph paper that is wound around a rotating drum. The drum rotates at a constant speed, typically about one revolution per day.
