🔍 Key Concepts

• Look closely at how letter codes are used in these symbols (for example, IG, FE, G). • Notice the difference between a system/installation symbol (like an inert gas system) and the symbol for a single piece of machinery or equipment. • Compare symbol (67) with nearby symbols (64) and (66) to see how different types of gas-related equipment are shown.

💭 Think About

• What does the large letter on symbol (67) most naturally stand for in the context of emergency fire‑control equipment? • If (64) already shows "IG" and (66) shows a gas tank with labels, what specific function might be left for the plain circular "G" symbol to represent? • Which option in the answers would most likely be marked by a simple, highly visible circular sign with a single letter rather than a detailed picture of the device?

✅ Before You Answer

• Verify which symbol in the chart actually shows IG for inert gas – does (67) have two letters or just one? • Check if any other symbol on the sheet is clearly used for a gas detector (sensor head or alarm symbol) so you don’t choose that twice. • Confirm that a switchboard or generator would be marked in a way that is easy to spot quickly on a fire control plan – which answer choice best matches a bold circular sign with a single "G"?