Buyers should prioritize the measurement range, typically covering 10^3 to 10^12 ohms/square, to ensure the device can categorize materials as conductive, dissipative, or insulative. Accuracy is critical; look for devices with a tolerance of ±10% and built-in temperature and humidity sensors, as environmental factors significantly impact ESD (Electrostatic Discharge) readings. Additionally, ensure the tester features parallel bar electrodes or supports external weighted probes (5 lbs) for compliance with professional laboratory standards.