Water Treatment Plant Operation Volume 2 Chapter 19

A confined space is defined as an area that is difficult to enter or exit, and has limited space for movement. If an individual needs to doc, crawl, climb, or squeeze into a space, it indicates that the space is restricted and meets the criteria of a confined space. Therefore, the correct answer is True.

Computerized controllers have the ability to be programmed and adjusted to suit specific processes. This means that they can be fine-tuned to optimize the control modes for a particular process. By tailoring their control modes, computerized controllers can ensure that the process operates at its most efficient and effective level. This flexibility and precision make computerized controllers a valuable tool in optimizing processes. Therefore, the statement "Computerized controllers can be programmed to precisely tailor their control modes to optimize a particular process" is true.

Directly pressurizing an air stream towards any part of the body or someone else's body can be dangerous and potentially harmful. It can cause injuries such as cuts, bruises, or even damage to sensitive body parts like the eyes or ears. Therefore, it is important to avoid directing air streams towards any part of the body or anyone else's body to ensure safety.

Rotameters are indeed used to indicate approximate liquid or gas flow. They consist of a tapered tube with a float inside that rises or falls based on the flow rate. As the flow increases, the float rises, and as the flow decreases, the float falls. The position of the float relative to a scale on the tube provides an approximate indication of the flow rate. Therefore, the statement "Rotameters are used to indicate approximate liquid or gas flow" is correct.

The statement is true because there are indeed two main types of chart recorders: strip chart recorders and circular chart recorders. Strip chart recorders use a long strip of paper that moves continuously, while circular chart recorders use a rotating circular chart. These types of recorders are commonly used in various industries to monitor and record data such as temperature, pressure, and flow rates.

Strains and sprains are common injuries that occur when muscles or ligaments are stretched or torn. These injuries can happen during physical activities or accidents. Water treatment facilities are not directly related to causing strains and sprains, so the statement is true.

Operators should learn how to shift all controllers to manual operation in order to be able to take over control of a critical system when necessary in an emergency. This is important because in emergency situations, there may be a need to quickly switch from automated control to manual control in order to prevent further damage or ensure the safety of the system. By learning how to shift controllers to manual operation, operators can be prepared to handle such emergencies effectively and efficiently.

Most flow instrumentation provides rate of flow and total flow values. Rate of flow refers to the amount of fluid passing through a certain point per unit of time, usually expressed in units such as liters per minute or cubic meters per second. Total flow refers to the cumulative amount of fluid that has passed through a system over a given period of time, usually expressed in units such as liters or cubic meters. These values are important in various industries and applications where monitoring and controlling fluid flow is necessary.

Reliable measurement systems can have a long service life by ensuring careful operation and regular maintenance of the instrument components. This means using the system correctly and following proper operating procedures to prevent any damage or wear. Regular maintenance, such as cleaning, lubricating, and replacing worn-out parts, is essential to keep the system in good working condition and prevent any potential issues or malfunctions. By taking these measures, the measurement system can continue to provide accurate and reliable measurements over an extended period of time.

The problem encountered with probes used to measure water depth is the accumulation of scum or sticking (such as grease) on the surface of the rods. This accumulation can interfere with the accuracy of the measurements taken by the probes.

Differential pressure sensing tubes (Venturi's) are not less accurate than orifice plates when used to measure flow. Both Venturi tubes and orifice plates are commonly used to measure flow, and their accuracy depends on various factors such as the design, installation, and calibration. While there may be slight differences in accuracy between the two, it is incorrect to state that Venturi tubes are inherently less accurate than orifice plates.

The person must have the capability to specify the control procedures and protective actions necessary to ensure a safe working environment in order to be confined space qualified. This means that they are able to identify and implement the necessary measures to prevent hazards and maintain safety within a confined space. This includes understanding the potential risks, determining the appropriate control measures, and effectively communicating and implementing these procedures to ensure a safe working environment for themselves and others.

Operators are expected to perform instrumentation O&M tasks such as standardizing instruments and implementing preventative maintenance measures. This involves ensuring that all instruments are calibrated and maintained according to set standards to ensure accuracy and reliability. Additionally, operators may need to repair or replace defective instruments to ensure smooth operations. They may also be responsible for specifying spare plans for new instrumentation systems and selecting the right computer programs for instrumentation controls to optimize performance.

Older water meters can under register due to bearing wear and gear train friction. These factors can cause the meter to function less accurately, leading to a lower measurement of water flow.

Instrument linearity refers to the ability of a device to accurately track a series of standards throughout its effective range. This means that the device is able to produce measurements that are proportional to the actual values of the standards being measured. In other words, if the device is perfectly linear, the measurements it provides will be directly proportional to the values of the standards. This is important in ensuring the accuracy and reliability of the device's measurements.

Totalizing is the correct answer because it refers to the process of calculating and presenting an ongoing running total of flow volumes passing through a meter. This term accurately describes the action of continuously adding up the flow volumes to provide a cumulative total. Cumulating, Metering, and Volumemetracating are not appropriate terms for this process.

The correct answer is "The smallest change in a process variable able to produce an appropriate response from an instrument." This means that sensitivity refers to the ability of an instrument to detect and respond to even the slightest changes in a process variable. A highly sensitive instrument will be able to accurately measure and control the process variable, while a less sensitive instrument may miss or inaccurately measure small changes.

A process variable refers to the physical or chemical quantity that is measured or controlled in a wastewater treatment process. This can include parameters such as temperature, pH level, dissolved oxygen, or pollutant concentration. By monitoring and controlling these variables, the wastewater treatment process can be optimized to ensure efficient and effective treatment of the wastewater.

The correct answer is to limit the effect pressure spikes or water hammer have on the instrument. This is because wearing pressure sensors fitted with surgery over range protection (snubbers) helps to mitigate the impact of sudden pressure changes or water hammer on the instrument. By doing so, the sensors can accurately measure and record the pressure without being affected by any spikes or surges, ensuring the instrument's proper functioning and preventing any damage or inaccuracies caused by these pressure fluctuations.

Digital instruments do not use a pointer against a marked scale. Instead, they display numerical values or readings digitally. Therefore, the statement is false.

False. This statement is incorrect. In reality, digital devices generally have lower power requirements compared to analog devices. This means that they do not require larger and more complex backup systems.

Single point detectors sense the fix elevation of liquid levels. This means that they can detect and measure the level of a liquid at a specific point or height, providing information about the liquid level at that particular elevation. They do not provide continuous level sensing or detect slight motion or water pressure.

When the tank is empty, there is no fluid for the pump to draw from. As a result, the suction side of the pump will experience low pressure, which will activate the low pressure switch. This switch is designed to prevent the pump from running in such a situation to avoid damage to the pump or any other components in the larger pump system.

In water treatment plants, the most common variables that are measured include flow, level, and pressure. Flow refers to the rate at which water is moving through the system, which helps in determining the efficiency of the treatment process. Level measurement is important to ensure that the water levels are maintained within the required range. Pressure measurement helps in monitoring the pressure within the system, which is crucial for maintaining the proper functioning of the equipment. These variables are essential for ensuring the effectiveness and efficiency of water treatment processes.

When air passes through a compressor, it can pick up moisture and oil particles from the surrounding environment. These liquids can contaminate the compressed air and cause damage to the compressor and downstream equipment. Therefore, special measures need to be taken to remove moisture and oil from the compressed air to ensure its quality and prevent any potential issues.

The correct answer is "Acute illness, Death, Death, Injury". This answer suggests that dangerous air contamination can lead to multiple hazards, including acute illness, death, and injury. The repetition of "Death" in the answer options might be a typographical error or a mistake in the question. However, it is clear that dangerous air contamination can have severe consequences on human health, causing acute illness and potentially leading to death or injury.

A water meter could over register due to a malfunctioning receiver, which may inaccurately measure the amount of water passing through the meter. Additionally, if the receiver malfunctions, it could cause the meter to continuously register water flow even when there is none, leading to an overestimation of water usage. A partially full pipeline could also cause the meter to over register, as the water may not flow smoothly and consistently through the meter, resulting in inaccurate measurements. Finally, if wrong gears are installed in the meter, it can affect the meter's ability to accurately measure water flow, leading to an overestimation of usage.

The most common types of pressure sensors are the Bourden tube and the Gauge. A Bourden tube is a flexible tube that deforms under pressure, allowing for the measurement of pressure changes. A Gauge pressure sensor is used to measure the pressure relative to atmospheric pressure. These two types of pressure sensors are widely used in various industries and applications due to their accuracy and reliability.

These gases may cause low oxygen levels and confined spaces because they have the ability to displace oxygen in the air. When present in high concentrations, they can reduce the amount of oxygen available for breathing, leading to a lack of oxygen and potentially creating a confined space where it is difficult for individuals to breathe properly.

Level probes are used in conditions where a mechanical system is impractical, such as in confined spaces or areas with limited access. They are also necessary when dealing with chemically active liquids, as mechanical systems may corrode or react with the liquid. Level probes are also used within pressurized tanks, where mechanical systems may not function properly due to the high pressure. Additionally, level probes are used within sealed tanks to accurately measure the level of liquids without the need for physical contact.

Level and pressure measurements can trigger on/off type controllers because they provide information about the quantity or amount of a substance or material. Level measurement determines the amount of material in a container or tank, while pressure measurement indicates the force being exerted by a substance. Both of these measurements can be used to activate on/off type controllers, which are designed to turn a device or system on or off based on certain thresholds or set points. For example, if the level of a substance reaches a certain point, the controller can activate a pump to add more material, or if the pressure exceeds a specific limit, the controller can shut off a valve to prevent damage.

Direct hydrostatic pressure and floats are both types of liquid level sensing devices. Direct hydrostatic pressure refers to measuring the pressure exerted by a liquid column to determine the level. Floats, on the other hand, are buoyant objects that rise or fall with the liquid level and can be used to indicate the level. Both methods are commonly used in various industries for monitoring and controlling liquid levels.

Chemical feeders, electrical motors, and turbidity meters are types of powered mechanical equipment that may suddenly start or move when you're not expecting it. This means that these devices have the potential to activate or initiate movement without any prior warning, which can be dangerous if proper precautions are not taken. It is important to be aware of this possibility and follow safety protocols when working with or around such equipment.