System yields at least seven digits of resolution per second of measurement time, and can resolve high frequencies up to 1.3GHz and low frequencies to 0.001mHz
The PFM1300 from TTi (Thurlby Thandar Instruments) is a UK-built hand-held frequency counter which can measure signals from 5Hz to 1300MHz.
Its low cost of under £100 puts it into the same price category as hand-held multimeters.
Despite its compact size and low cost, the PFM1300 incorporates many advanced features.
In particular, it uses the 'reciprocal counting' technique to achieve high measurement resolution at all frequencies. Reciprocal counting uses multiple period measurements followed by computation of the reciprocal value.
This results in a high-resolution measurement regardless of the signal frequency. The system yields at least seven digits of resolution per second of measurement time, and can resolve low frequencies to 0.001mHz (0.000001Hz).
The frequency range is from 5Hz up to 1300MHz with excellent sensitivity throughout (typically 15mV).
A low-pass filter can be selected when required.
Signals can also be displayed in terms of period as an alternative to frequency from 5Hz up to 25MHz.
A 'hold' key allows readings to be frozen on the display whenever required.
The counter is housed in a robust ABS case measuring 81x173x30mm and weighing less than 200g.
A large LCD display of very high contrast with 11.5mm high characters is incorporated.
The display incorporates 15 annunciators covering measurement function, measurement time, units, overflow, trigger activity and low battery.
Low power consumption circuitry ensures long battery life.
A 'push to measure' facility is also incorporated which provides an immediate reading on the press of a key followed by an automatic power-down after 15 seconds, thus ensuring maximum battery life when continuous signal monitoring is not required.
The PFM1300 costs £99.00 (plus VAT).