Intelligent Digital Frequency Meter Counter LED Relay Output Countdown Timer 100khz DC8‑24V Item Type: Intelligent Digital Frequency Meter Ambient Temperature: 22℃ Technical Index: 1. Measurement Accuracy: ±0.1%, Reading: ±1 word 2. Display Mode: 0.56 red LED 3. Four digit reading 4. Display Refresh Rate: >3 Times per second 5. Working Power Supply: AC DC8-24V, 40mA 6. Over Range Display: "1" or" -1" is displayed in the first place, and the last three digits are not displayed Function: 1. Input Pulse Signal: NPN PNP collector open circuit, contact switch, non contact switch, level pulse 2. Input Signal Voltage: Low Level: -30V-0.6V, High Level: 4-30V 3. Measuring Range: Frequency: 9999Hz, 999.9hz, 99.99khz three levels, automatic switching selection 4. Maximum Input Frequency: 10KHz, 100khz, 300khz