Precision Timer / Stopwatch Calibrator

The Timer Calibrator TFC-1901 is a precision instrument. It is Primarily designed to generate the accurate time intervals for calibrating time-related devices, ensuring traceability to National/International standards. Built with a internal 10MHz OCXO/TCXO time base Oscillator or External input Frequency from standard Lab source and also with Non contact RPM calibrating source all in a single unit — with potential-free MOSFET trigger output connector terminal to support an external Multi-stopwatch fixture (Model : TFC-19F) — to eliminate manual START/STOP timing error and 10MHz OCXO/TCXO Reference frequency output is provided on rear side terminal of Instrument.

Technical Specifications

• Model: TFC 1901
• Display: 4.3” Multi-colour TFT touchscreen display.
• Range: Digital Electronic Stopwatch: 100 ms to 86400.00000 s; Mechanical Stopwatch & Electronic Industrial Timer: 1 s to 86400.00000 s.
• Resolution: 10 µs to 1 s (selectable: 0.00001 / 0.0001 / 0.001 / 0.01 / 0.1 / 1 s).
• Display Format: Time in HH:MM:SS.fraction.
• Mode 1 – Precision Stopwatch / Timer: High-resolution elapsed-time counter driven directly from the Precision internal oscillator reference, supporting free-run stopwatch and preset auto-stop timer operation with Master and DUC triggering.
• Time Base: Directly referenced to the internal 10 MHz OCXO/TCXO.
• Auto-Stop: Auto-stop at user-set target time.
• Master vs. Calibration Mode: Master: touch control, outputs enabled, Auto-Stop available, Up/Down count; Calibration: external-input control, outputs disabled, input detection enabled, no Auto-Stop.
• Accuracy: Digital Electronic Stopwatch – OCXO: ±(5.02 × 10⁻⁸ × Te + 2 ms); TCXO: ±(1.003 × 10⁻⁶ × Te + 2 ms); Mechanical Stopwatch & Electronic Industrial Timer – OCXO: ±(5.02 × 10⁻⁸ × Te + 5 ms); TCXO: ±(1.003 × 10⁻⁶ × Te + 5 ms), where Te = elapsed time.
• Trigger I/O: Master generates START/STOP/RESET output pulses (30 µs) and continuous output; Calibration accepts external START/STOP/RESET, pulse mode and selectable continuous mode.
• Mode 2 – Frequency Totalizer: Precision pulse totalizer that counts input events entirely in hardware, converts the count to elapsed time at the selected resolution, and simultaneously measures live input frequency referenced to the OCXO/TCXO.
• Run Time: 24 hours continuous run at 100 kHz without rollover (1.728 × 10¹⁰ pulses).
• Input / Counting: Dedicated pulse-count input with standard logic-level pulse train and fully hardware-based counting.
• Frequency Measurement: Measured against OCXO/TCXO reference; range from 1 Hz to 100 kHz.
• Resolution / Frequency Map: 0.00001 s ↔ 100 kHz, 0.0001 s ↔ 10 kHz, 0.001 s ↔ 1 kHz, 0.01 s ↔ 100 Hz, 0.1 s ↔ 10 Hz, 1 s ↔ 1 Hz.
• Mode 3 – RPM Generator: Front-panel LED blinks at 50% duty cycle, matching the RPM value for visual RPM checking using a stroboscope or similar method.
• Range for Non-contact: 0 to 204,000 RPM.
• Output / Conversion: Front-panel LED output, 50% duty-cycle square wave; f (Hz) = RPM / 60.