VERTICAL STAFF GAUGES
A staff gauge normally consists of a measuring plate fixed to a post set in concrete. The measuring plate is typically made up of coated steel or stable FRP with increasing increments of 0.01 m. The staff gauge is fastened to a concrete or steel pole that has slots to adjust the level of the plate. Staff gauges may also be painted on a well-established and stable structure, like a bridge pier or retaining wall. At all hydrometric stations a staff gauge is required to measure the water level. The staff gauge is used as the main way of obtaining the level, or as a reference gauge to cross reference the water level recorder.
The site requirements for installing a staff gauge should include being attached to a stable bank, or to a bridge pier or reservoir wall. It should be accessible so that it can be read at any time without any obstructions in the way. To reduce measuring errors they should be place in an area of little turbulence and wave action.
If a station has a stilling well with a recorder inside, staff gauges are placed inside and outside the well in order to help level the gauge. Two permanent benchmarks of known level should be close to the site in order to achieve accurate level readings.
Installation aspects
Vertical gauges are typically installed in pieces of 2.0 meter lengths; there should be enough length so that it surpasses the maximum flood level. The zero of the gauges should correspond with the lowest possible water level when dealing with water controlled by a weir. For naturally controlled stations, the zero must be lower than the lowest water level in rivers that are relatively constant year round and lower than the lowest bed level in rivers that do not maintain a water level year round...
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...densation of water in the vent tube and in the sensor.
Advantages and limitations of pressure sensors
Advantages: - they give a direct reading of depth, do not require a stilling well to damp out water level oscillations and are thus relatively easy and cheap to install even though some form of protection is strongly advised. The cable does not have to be installed vertically and transducers are ideally suited for interfacing with data logging systems.
Limitations: - the levels of accuracy are typically limited to 0.1% of full scale, they are susceptible to changes in environment (manufacturer’s stated accuracy is often at a constant reference temperature), they can be affected by changes in density of the water column, are sometimes susceptible to flow (velocity head) and electrical noise effects and are liable to drift over relatively short time scales (< 1 year).
When the liquid level is above the calibration line on the pipette, remove the bulb quickly and put your thumb or index finger over the pipette. Carefully “roll” finger to the side and allow the liquid to drop until the meniscus is level with the mark. Then hold the pipette over the flask to receive the liquid and remove the finger. Allow the liquid to drain out.
Discussion: The percent of errors is 59.62%. Several errors could have happened during the experiment. Weak techniques may occur.
The buret nozzle was closed and the final amount of acid in the buret was recorded. The stir bar was taken out of the flask using a bar magnet.
Sticky notes were used to label each beaker and petri dish with the concentration of NaCl (0%, 5%, 10%, 15%, 20%).
The water baths were well controlled, and the thermometers helped to control the desired temperatures. the water baths I think were accurate enough but having two thermometers in each bath maybe would have helped to be hold the temperature readings more accurate.
Possible errors include leaving in the test strips for too long, draining too much water into the aquatic chamber (overfilling/watering), and inverting the tubes for a shorter amount of time than required. Although there are many possible human errors that could be committed in this lab, it is important to note that the tools used for water testing could be expired and could therefore not work as well at detecting the proper levels for dissolved oxygen, pH, and nitrate.
Summary and procedures: the use of the different types of apparatus to get the correct results is always knowing it functionality and the correct significant digits. We always must make sure the balance should be 0.000 g when it is completely empty. In the case of the electric balance, the tray must to be clean and free of water or dirt, this machine is very accurate and precise. In the use of the flask and beaker, those should be cleaned before and after the use, that is how we avoid and create accidents for unknow chemicals or substances that were used before in the containers. Starting with the procedure, first is determine the mass for each balance in use, then record all the necessary data of that.
The federal government has taken action in requiring “each federal agency to review its dam-safety activities and to strengthen its dam safety programs” (Gunn, 2006). Dams are now required to be inspected annually, with a detailed report of the dam every three years (Gunn, 2006). Moreover, “Congress passed several acts authorizing a natural dam-safety program” which works to protect Americans from dam failure, in addition to installing more instrumentation to monitor the dam’s stability (Gunn, 2006). Sherard (1987b) proposes that having bureaucracies design dams is dangerous and should be avoided; Seed and Duncan (1987) added that it should be reviewed by an outside group of engineers to ensure that no possible design flaw has been over looked. The Teton Dam was an inadequate and unacceptably designed for this environment, and any unanticipated conditions and problems with materials, such as low quality, should be taken into account (Sherard, 1987b; Seed and Duncan, 1987). The wet seam was a new discovery and a lesson in the hydrogeologic properties that were a result of the situation created by the Teton Dam (Sherard, 1987b). An additional lesson is that filling the reservoir at the recommended speed, in controlled conditions is essential, so that it is possible to lower the
In industry, the performance specifications for a particular pump may be known, but the tests are usually based on water as the pumping medium. For liquids of significantly higher viscosity than water, these performance curves may only be accurate at certain flow rates, or they might not be valid at all, and it might be necessary to recalibrate the specifications for higher viscosity liquids.
.... Without knowledge of the reliability and validity of these two instruments we are unable to know if the instruments are consistent or if they measure what they intend to measure.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
Possible sources of error in this experiment include the inaccuracy of measurements, as correct measurements are vital for the experiment.
Certain conditions can cause the line on the hydrograph to be tall and thin and other conditions can cause it to be short and wide. Peak discharge is the term used to describe the maximum amount of discharge from the river over the period of time recorded; this peak discharge can be high or low depending on a lot of conditions. Climatic factors are the most obvious conditions that can affect the flood hydrograph. If the precipitation is very intense and there is a lot of it then the hydrograph is likely to have a high peak discharge where as if the precipitation is low-intensity and there is a small amount then the graph will have a gentle ascending limb. [IMAGE][IMAGE]The ascending limb is the first part of the line on a hydrograph that rises to the peak discharge.
(a) A rain gauges (b) A wind vane (c) An anemometer (d) A hygrometer (e) hydrometer
...se due to the acidic environment. The BOD result will be less than it should be. The pH level should be monitored as well as the temperature. [4]