Technology & Digital Tools Flashcards

An ORP (Oxidation-Reduction Potential) sensor in a pool automation system primarily measures which water quality parameter?

Answer: Sanitizer effectiveness

ORP sensors measure the oxidizing power of the water, which directly indicates how effectively the sanitizer (such as chlorine) can kill pathogens.

A digital turbidity meter reading above what NTU value typically indicates a pool should be closed until clarity is restored?

Answer: 3 NTU

Most health codes require pool closure when turbidity exceeds 1 NTU at the drain, but 3 NTU is a commonly cited threshold at which the main drain is not clearly visible.

When calibrating a digital pH probe, what is the recommended sequence of buffer solutions to use?

Answer: pH 7, then pH 4 or pH 10

Two-point calibration starting at the midpoint buffer (pH 7) then a boundary buffer (pH 4 or pH 10) provides the most accurate slope correction for a digital pH probe.

A Variable Frequency Drive (VFD) on a pool circulation pump primarily saves energy by:

Answer: Adjusting motor speed to match actual flow demand

VFDs reduce energy consumption by varying pump motor speed to meet actual flow requirements; pump power consumption drops with the cube of speed reduction.

In a pool automation system, a 4–20 mA analog signal from a chemical sensor typically represents:

Answer: A proportional measurement across the sensor's full range

A 4–20 mA current loop is an industry-standard analog signal where 4 mA represents the minimum reading and 20 mA represents the maximum, providing proportional measurement.

What is the primary advantage of using a peristaltic chemical feed pump over a diaphragm metering pump in a pool system?

Answer: The chemical contacts only the tubing, reducing corrosion risk

In a peristaltic pump, the chemical only contacts the flexible tubing and never touches the pump mechanism, making it ideal for corrosive pool chemicals.

A pool controller shows a chlorine residual of 2.0 ppm but swimmers are still reporting eye irritation. The MOST likely digital tool to use next is:

Answer: A photometric colorimeter to verify the free vs. combined chlorine ratio

Eye irritation despite adequate total chlorine typically indicates high combined chlorine (chloramines); a photometric colorimeter can separately measure free and combined chlorine to confirm.