QNFS Hvac Technician Interview Questions and Answers

The unit of resistance is ohm (Ω), named after German physicist Georg Simon Ohm.

• The unit symbol for resistance is Ω

• Resistance is measured using an ohmmeter

• 1 ohm is equal to 1 volt per ampere (V/A)

The unit of current is Ampere (A)

• The unit of current is named after the French physicist Andre-Marie Ampere

• 1 Ampere is defined as the flow of 1 Coulomb of charge per second

• Commonly used prefixes for current include milliampere (mA) and microampere (μA)

To install a temperature transmitter, you need to properly mount the transmitter, connect the wiring, configure the settings, and test the transmitter.

• Mount the temperature transmitter in a suitable location near the temperature source.

• Connect the wiring according to the manufacturer's instructions, ensuring proper grounding.

• Configure the settings such as range, output signal, and calibration using the transmitter's di...read more

Instrumentation equipment refers to devices used to measure, control, and monitor various parameters in industrial processes.

• Instruments like pressure gauges, flow meters, and temperature sensors are commonly used in instrumentation.

• Control valves and actuators are used to regulate the flow of fluids or gases.

• Programmable Logic Controllers (PLCs) are used for automation and control of processes.

• Analytical instruments l...read more

A PLC panel wiring diagram is a visual representation of the electrical connections and components in a programmable logic controller panel.

• A PLC panel wiring diagram shows the layout and connections of various components such as power supplies, input/output modules, relays, and sensors.

• It helps technicians understand how the electrical signals flow within the panel and how different devices are interconnected.

• The diag...read more

A control valve is a device used to regulate the flow of fluid or gas in a process system.

• Control valves are commonly used in industries such as oil and gas, chemical, and power plants.

• They can be operated manually or automatically through an electrical or pneumatic signal.

• Control valves consist of a valve body, actuator, and positioner.

• They can control variables such as flow rate, pressure, temperature, and level.

• Exam...read more

A transmitter is a device used in instrumentation to convert a physical measurement into an electrical signal.

• Transmitters are commonly used in industries such as oil and gas, chemical, and power plants.

• They are used to measure variables such as pressure, temperature, flow rate, level, and pH.

• Transmitters typically consist of a sensing element, signal conditioning circuitry, and an output signal.

• The sensing element det...read more

Flow meters are devices used to measure the flow rate of a fluid or gas.

• Flow meters are commonly used in industries such as oil and gas, water treatment, and manufacturing.

• They can measure flow rates in various units such as liters per minute, cubic meters per hour, or gallons per minute.

• Different types of flow meters include electromagnetic, ultrasonic, turbine, and differential pressure flow meters.

• Flow meters can be...read more