In the product specifications of the T8200PRO-G, there is a statement: "T8200PRO-G is a resonance frequency tester based on a scalar network analyzer." This means that the T8200PRO-G is a resonance frequency tester built on a scalar network analyzer. So, what exactly is a "scalar"? Below is an excerpt from an online explanation for your reference:

A Network Analyzer (NA) can be categorized into a Vector Network Analyzer (VNA) and a Scalar Network Analyzer (SNA) based on its functionality. Since a Vector Network Analyzer can measure both amplitude-frequency and phase-frequency characteristics—fully encompassing the capabilities of a Scalar Network Analyzer (which can only test the amplitude-frequency characteristics of a device)—the market today primarily features Vector Network Analyzers.

"A Vector Network Analyzer measures the amplitude and phase responses of a device's network ports to frequency/power-swept test signals, thereby determining the network characteristics of the device. It combines technologies such as spectrum analysis, signal generation, and signal separation, earning it the title of 'King of Instruments.' It is an essential testing and measurement instrument in the RF and microwave fields and serves as the foundational form for many industry-specific instruments." — Wikipedia