Frequency meter digital billboard F246
Also this device may be referred to: F-246, F 246.
F246 digital frequency meter shield is designed to measure the frequency of industrial AC networks.
Dimensions - 80×160×250 mm.
Rated frequency measurement - 50 Hz.
Harmonic distortion of the input voltage measuring circuit - not more than 15%.
Worker measuring range - from 48 Hz to 52 Hz.
Extended measuring range - from 45 Hz to 55 Hz.
The basic error of frequency meter:
- in the range from 49.5 Hz to 50.5 Hz - not more than ±0,02%;
- in the working range - not more than ±0,04%;
- extended range - not more than ±0,1%.
Input voltage measuring circuit - 220±44 V; 100±20 V; 2±1 V.
Input impedance frequency meter:
- for measuring circuits 200 V and 100 V - not less than 40 Ohm;
- for measuring circuit 2 V- not less than 600 Ohm.
Speed frequency meter F246 - 4 rev./sec.
The external magnetic field, which does not affect the accuracy of the frequency - 400 A/m.
Maximum permissible variation in the induced temperature deviation - half of the maximum permissible basic error for every 10° C.
Maximum permissible variation in the change in voltage within ±15% of nominal - half of the maximum permissible basic error.
Modes of operation frequency F246:
- launch an internal automatic;
- launch external frequency with no more than 4 Hz.
External trigger signal parameters:
- pulse amplitude logical "1" - from 2 V to 5.25 V;
- residual voltage corresponding to a logical "0" - from -0.4 V to 0.8 V;
- pulse - not less than 10 mcs.
Frequency meter F246 provide access to the external connector of the measured frequency in BCD 8-4-2-1 (CPU) and the end of the measurement signal.
Outputs coded signals frequency consistent with chips series - 134, K134, 136, K136, K158.
- no more than five units of series 134, K134;
- no more than three units of series 136, K136;
- no more than two units K158 series.
Parameters of the output signals load resistance of at least 150 Ohm:
- logical "1" - from 2.4 V to 5.25 V;
- logical "0" - from 0 to 0.4 V;
- the duration of the measurement signal the end - not less than 50 mcs.
Digital readout device provides an indication of five bits of frequency values from 45 000 Hz to 55 000 Hz with a resolution of 0.005 Hz.
Electrical isolation of power circuits with respect to the protective earth terminal frequency withstand voltage of 1.5 kV AC practically sinusoidal frequency of 50 Hz.
Input frequency meter F246 grounded.
The insulation resistance of power circuits with respect to the protective earth terminal:
- in normal conditions of use - not less than 20 MOhm;
- at a temperature of +50° C - not less than 5 MOhm.
Frequency meter resistant to vibrations with a frequency of 25 Hz and an amplitude of 0.1 mm.
MTBF - not less than 7000 hours.
Power consumption - not more than 10 V·A.
Frequency weight - 2 kg.
Operating conditions of frequency F246:
Ambient temperature - from +5° C to +50° C.
Relative humidity at +35° C - up to 80%.
Power supply voltage - 220±33 V; 100±15 V.
Supply frequency - 50±5 Hz.