Daily Difference Calibrator


High precision OCXO are built in

Support instantaneous measurement of daily difference, monthly difference and yearly difference

Non-contact or contact measurement way could be selected.

Frequency and time interval measurement function are also supported

7” touch screen display, voice broadcast PPM measurement result.


Instantaneous Daily Difference Measurement
Frequency32.768KHz, 1Hz
ObjectElectric Stopwatch, Electric Energy Meter, Crystal, Quartz Clock, etc.
MethodNon-contact or contact
ItemsPPM, s/d, s/m, s/y
RangeDaily difference: -10.000 ~ +10.000 (s)
Monthly difference: -300.000 ~ +300.000 (s)
Allowed Error RangeInternal frequency standard-Daily difference: ±0.01s, Monthly difference: ±0.3s
External frequency standard-Daily difference: ±0.001s, Monthly difference: ±0.03s
Time/Frequency Measurement
ResolutionFrequency: 8 digits/sTime Interval: 5ns
Signal LevelPulse, TTL Level
Time Base Input
Frequency5MHz or 10MHz
Built-in OCXO
Frequency 10MHz
Daily Aging≤1×10-9/day
Power on ≤1×10-8
Frequency Accuracy≤1×10-7
Second Stability≤3×10-11/s
General Characteristic
Power AC220 (1)V, 50(1)Hz, <50VA
Work EnvironmentTemperature: 0~+40℃, RH:20~80%
Dimension &Weight364×155×328 mm, approx. 2KGs

Questions & Answers

SF2004 Daily Difference Calibrator

Q: What’s the SF2004 daily difference calibrator?

A: The SF2004 daily difference calibrator is a multi-functional calibrator developed according to ‘verification regulation of JJG 488-2018 instantaneous diurnal difference meter’. The measurement way that SF2004 used is to transform the oscillating signal from the Clock to the corresponding electrical signal by using the magnetic-electro converting type sensor, then measure the difference between the period of electrical signal and the nominal value by counting method to calculate the daily difference. Additionally it can also measure the electric product which is built-in 32768Hz crystal oscillator, and directly measure the clock error of smart energy meter which output 1Hz, even the measure the frequency of Pulse and the time interval of two Pulses.

Q: What’s the application area of SF2004 daily difference calibrator?

A: According to its function, it could be used in metrology verification department, product quality inspection organization and producing company of clock and smart electric energy meter.

Standard Accessories

BNC Cable: 1

Power Cord: 1

CD (Users Guide): 1

Sensor + Connection wire: 1