When selecting electrodes for Ion-Selective Electrode (ISE) analyzers, you must prioritize measurement range, slope sensitivity, and response time. Ensure the electrodes for K+, Na+, Cl-, Ca2+, and Li+ have a slope within the manufacturer's specified range (typically 50-65 mV/decade) to ensure linear accuracy. Additionally, verify the service life, which should ideally be 6 to 12 months under normal laboratory throughput, and check for low drift rates (<1% per 24 hours) to minimize frequent recalibration.