Aim TTi PFM3000 INSTRUCTION MANUAL [ml]

PFM3000

Portable Frequency Meter

INSTRUCTION MANUAL

Table of Contents

Introduction 1
Specification 2
Safety 4
Operation 5
Calibration and Maintenance 6
Securite 7
Fonctionnement 8
Calibration et Entretien 9
Sicherheit 10
Betrieb 11
Eichung und Wartung 12
Sicurezza 13
Funzionamento 14
Taratura e Manutenzione 15
Seguridad 16
Functionamiento 17
Calibración y Mantenimiento 18

Introduction

The PFM3000 is a portable frequency meter with a large 11.5mm 8½-digit liquid crystal display
(LCD). The frequency range is 3Hz to 3GHz and measurement capabilities include frequency and
period with push-to-measure and auto power-down functions.

A hold function is available which allows any reading to be frozen and displayed indefinitely.
Input A is a high impedance input (1MΩ)or frequencies in the range 3Hz to 125MHz. Input B is a

nominal 50Ω input for frequencies in the range 80MHz to 3GHz.
The instrument uses a reciprocal counting technique to provide high resolution at all frequencies.

At least 7 significant digits of answer are produced per second of measurement time.
A low pass filter can be selected to ensure stable readings at low frequencies.
Indicators show measurement function, measurement time, low battery and the units of the answer

which may be Hz, kHz, MHz, ns, us, ms or s.
The low power design gives typically 20 hours battery life from a 9 volt alkaline cell. Use of the

power saving push-to-measure functions will avoid wasting battery life by automatically switching
the unit off after a short time.

The instrument has a robust ABS case.

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MEASUREMENT FUNCTIONS

Crystal Oscillator Frequency:

Frequency (Range A)

Frequency Range: 3Hz to >125MHz
Resolution: 10

Frequency (Range B)

Frequency Range: 80MHz to >3000MHz
Resolution: 1Hz to 10kHz (see below)

Period (Range A only)

Period Range: 8ns to 330ms
Resolution: 10

Measurement time

Selectable as 10s, 1s or 0.3s.

Resolution

The displayed resolution depends upon the measurement time and the input frequency. Eight or
nine digits are displayed for a 10 second measurement tim e. Six, seven or eight digits are displayed
for the shorter measur ement times depending on input frequency. Usable resolution can be further
reduced by noise, especially at low frequencies.

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Hz to 100Hz (see below)

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ns to 1us (see below)

Specification

Accuracy

Measurement accuracy is the sum of timebase accur ac y and measur em ent r es olut ion plus one
count.

TIMEBASE

Initial Oscillator Adjustment Error: ± 2ppm (closed-case adjustment by user)
Oscillator Temperature Coefficient: Typically less than

Oscillator Ageing Rate: <± 5ppm/year

OPERATING FUNCTIONS

Press to measure

With the power switch off, pressing any of the function select k eys will power the instrument up in
the corresponding function. The instrum ent will automatically switch off 15 seconds af t er the last
key-press.

Hold

Pressing the Hold key will stop further measurem ents being made and the current measured value
will remain in the display, with the Hold indicator on, until the Hold k ey is press ed again.

10MHz

± 0.3ppm/°C 18°C to 28°C,
± 10ppm –20°C to 70°C

Noise filter

The Filter key controls a low pass filter, with a cut-off frequency of about 50kHz, to ensure stable
readings at low frequencies.

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Signal activity indicator

time.

Operating Range:

+5°C to +40°C, 20% to 80% RH

Storage Range:

20°C to +60°C

Environmental:

Indoor use at altitudes up to 2000m Pollution Degree 2

Size:

81mm x 178mm x 30mm (WxLxD)

Weight:

190gms excluding battery

needed).

When no input sig nal is detec t ed t he Trig indicator will be off, indicating t hat no m eas ur em ent is
possible. The gate time indicator flashes until the first measurement interval is complete.

INPUT SPECIFICATI ONS

Input A

Input Impedance:
Frequency Range: <3Hz to >125MHz
Sensitivity: Sinewave - 15mVrms 10Hz to 125MHz

Input B

Input Impedance:
Frequency Range: <80MHz to >3GHz
Sensitivity: Sinewave - 12mVrms 80MHz to 2GHz, 25mVrms to 2.5GHz,

Maximum Input Voltage

Input A and Input B:

Note that the inputs will not be damaged if subjected t o an acc idental short-term connection to a
50/60Hz line voltage not exceeding 250V rms.

1MΩ//20pF (AC coupled)

50Ω nominal (AC coupled)

50mVrms to 3GHz

dc; 30V rms 50/60Hz with respect to ground

30V
to 1Vrms above 1MHz

, reducing

POWER REQUIREMENTS

Battery Type: 9V PP3 alkaline
Battery Life: Typically 20 hours
Low Battery Indicator: ‘Bat' shows in display when approximately 10% of battery life

GENERAL

Display:

Safety & EMC: Complies with EN61010-1 & EN61326-1.

remains.

8½ digit LCD,

11.5m m high (0.45”);
15 annunciators show measurement units, input, mode and

–

For details, request the EU Declaration of Conformity for this
instrument via http://www.aimtti.com/support

(serial no.

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Safety

This instrument is Safety Class III according to IEC classification and has been designed to m eet
the requirements of EN61010-1 (Safety Requirements for Electrical Equipment for Measurement,
Control and Laboratory Use). This instrument has been test ed in acc or dance with EN61010-1 and
has been supplied in a safe condition. This instruction manual contains some infor m at ion and
warnings which have to be followed by the user to ensure safe operation and to retain the
instrument in a safe condition. This instrument has been designed for indoor use in a Pollution
Degree 2 environment in the temperature r ange 5°C to 40°C, 20%-80% RH (non-condensing).
It may occasionally be subjected to temperatures bet ween +5°C and –10° C without deg r adat ion of
its safety. Do not operate while condensation is present. Use of this inst r ument in a manner not
specified by these instructions may impair the safet y prot ect ion pr ovided. Do not oper at e the
instrument outside its rated supply voltages or environmental range.

WARNING! All accessible parts will be at the same voltage potential as the outer of the BNC input
sockets: to maintain user safety it is therefore essential that neither input is connected t o a voltage

above 30Vdc or 30Vrms with respect to ground
accidental connection to an AC line voltage up to 250V rms, 50/60Hz, users will be at risk if the
instrument 'ground' is connect ed to such hazardous voltages. The apparatus shall be
disconnected from all voltage sources bef or e it is opened for any adjustment, replacement,
maintenance or repair, including replacement of the battery.

. Note that although the inputs will withstand

Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided
as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of the
hazard involved.

Do not wet the instrument when cleaning it. The following symbol is used on the instrument and in
this manual:

meaning CAUTION. Damage to t he inst r ument may occur if these
precautions are ignored.

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Power

To fit or r eplace the battery, undo the battery cover screw and lift off the cover. Fit the battery snap,
observing the correct polarity, insert the battery into the compartment and replace the cover.
WARNING! To prevent shock hazard, all inputs must be removed before changing the battery.

Turn the instrument on by sliding the power switch on the left-hand side of the instrument to ON.
With no sig nal connect ed the display should show 0.0, the Function annunciator (default FREQ A),

and the selected measurement time annunciator flashing (default 0.3s).

Function and Measurement Time Selection

Pushing any of the keys, FREQ A, FREQ B or PERIOD A, will set the instrument to the respect ive
function and the selected funct ion will be shown by annunciators in the LCD. Select the
measurement function appropr iat e t o t he s ig nal t o be m eas ur ed and connec t t he s ig nal t o the
corresponding BNC input; the TRIG annunciator should show in the display to indicate that the
signal has been detected. Measurement time is selected by pressing t he TIME key, the selected
time being shown by the appropriate annunciator in the LCD. Switching between FREQ A and
PERIOD A will immediately convert the present measurement; ot her wise a change of function or
measurement time will initiate a new measurement. This may also be accomplished without a
change of function or measurement time by pressing the key corresponding to the function
currently selected; the new measurement will start immediately.

Operation

Inputs

When a measur em ent is star t ed, the measurement time annunciator flashes unt il a true result for
that selected measurement time is displayed, at which point the annunciator stays on. Further
display updates then show the running average of the signal behaviour over the last 0. 3s ( 1
update), 1s (2 updates per second) or 10s (1 update per second) depending on the selected
measurement time. Note that if a 1s or 10s measurement time is selected, star t ing or restarting the
measurement gives a true result with at least 6 dig its af t er 0. 3s , followed by at least 7-digits after 1s
and, finally, at least 8-digits after 10s (if 10s measur em ent is s elect ed) .

The frequency and period measurem ent functions both produce at least 7 digits of answer per
second of measurement time and t he units and decimal points are adjusted automatically to give
the answer in the most convenient units. Pressing the HOLD key will stop the measurem ent and
freeze the display with the 'Hold' annunciator showing in the LCD. Hold may be cancelled by a
second press of the HOLD key. With the power switch in the off position pressing one of the
function keys will power the instrument on and set the selected function. The instrument will then
function normally and respond to all key presses.

After a period of about 15 seconds with no key presses t he inst rument will automatically power
down to conserve the battery. Switching the ON/OFF switch ON then OFF during t hese 15 s econds
will have no effect.

Socket A is used for frequencies in the range 3Hz to 125MHz. Input impedance is 1MΩ in parallel
with 20pF. Care should be taken when measuring input signals above 350mV rms ( the onset of
diode clipping) with poor signal to noise ratios as under these circum stances it is possible for noise
to generate spurious counts. To ensure a correct count, therefor e, noisy sig nals should be
attenuated externally before being presented t o t he c ount er. A convenient attenuation f ac t or of 10
can be achieved by the use of a x10 oscilloscope probe. The A socket will accept most t ypes of
waveform – including sine, square and pulse signals. With pulse waveforms the mark to space ratio
should not exceed 90% and the minimum pulse width should be greater than 3ns. A low pass filter
with a cut-off frequency of 50kHz may be selected by pressing the FILTER key. The message FILT
ON shows briefly in the display and the Filt annunciator is turned on; pressing FILTER a second
time turns the filter off (display briefly shows FILT OFF and the Filt annunciator goes off). Use the
filter with low frequency large amplitude signals.

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