input impedance of a network is the measure of the opposition to current flow
(impedance), both static (resistance) and dynamic (reactance), into the load
network being connected that is external to the electrical source. If current
input is needed, it is ideal that the input impedance is low, such as a TIA which
is a converter for current to voltage. If we want a high voltage across the
input impedance, we increase the impedance, as this will in turn increase the voltage.
Broadband – transmits many signals through the whole band, allows you to
send and receive at the same time
Baseband – uses the whole band to submit one signal of information, this
allows you send or receive data, but not at the same time
can be used in 2 different types of ways –
Bandwidth is defined as a range within a band of
frequencies or wavelengths. Bandwidth is also defined as the amount of data
that can be transmitted in a fixed amount of time. For digital devices, the
bandwidth is usually expressed in bits per second (bps) or bytes per second.
For analog devices, the bandwidth is expressed in cycles per second, or Hertz
Sensitivity is defined as the ratio of
the output signal to the corresponding input signal for a specified set of
operating conditions. Similarly, gain is the ratio of the amplifier output
signal voltage to the input signal voltage. If the amplification ratio is less
than unity, then it is called the attenuation. The sensitivity of a measuring device or instrument
depends on the principle of operation and the design. Many devices or
instruments are designed to have a linear relationship between input and output
signals and thus provide a constant sensitivity over the operating range.
can be defined as the amount of uncertainty in a measurement with respect to an
absolute standard. Accuracy specifications usually contain the effect of errors
due to gain and offset parameters. Offset errors can be given as a unit of
measurement such as volts or ohms and are independent of the magnitude of the
input signal being measured. An example might be given as ±1.0 millivolt (mV) offset
error, regardless of the range or gain settings. In contrast, gain errors do
depend on the magnitude of the input signal and are expressed as a percentage
of the reading, such as ±0.1%.
Resolution can be in a specification labelled as maximum resolution,
this is the smallest value found by the meter on the lowest range. In many specifications for DMM (Digital
Multimeter), range and resolution are related. Some offer an auto range
function, it selects the best range for the measurement, and with this you get
the relevant reading and the best resolution.
Resolution refers to how fine a measurement a meter can make. By knowing
the resolution of a meter, you can determine if it is possible to see a small
change in the measured signal.
specifications will ensure the validity and consistency of measurements when
testing electronic components because the test specification is a list of rules
that need to be adhered to so that the component is what is says to be without
is very important that the components are functioning correctly and when a
consumer buys the product they hope that it does what it is supposed to do but
this is not always the case. It is the engineer’s job, to ensure that each and
every component is tested and deemed safe to use.
The implications of a poor test
specification for any component are enormous in terms of Cost, Safety and
The component tolerance
The way that the equipment is connected
The type of test and measurement equipment used
Below I have devised a list of test
parameters, this will include:
An electronic test specifications
are a set of rules which must be applied when testing an electronic component
or system. This means that whenever the component or system is tested it is
tested in the same way. Therefore we should expect the same or very similar results
each time a test is carried out. When tested in this way, components or systems
whose behavior does not fall within the expected parameters are deemed to be
A Test Specification is a detailed
summary of what scenarios will be tested, how they will be tested and how often
they will be tested for a given feature. Test Specifications can be used to
verify the compliance to internal, national or international standards. These
standards ensure the validity and consistency of the measurement.
your report explain the importance of test specifications as an aid to ensuring
the validity and consistency of measurements taken during testing of electronic
are used with known values for selected points covering the range of interest
are measured with the instrument in question. Then a functional relationship is
established between the values of the standards and the corresponding
instruments have a degree of accuracy that degrades over time. This is
typically caused by normal use however, a degrade in accuracy can also be
caused by electric or mechanical shock. In addition to this, hazardous
manufacturing environment can also effect the accuracy on the instrument.
Calibration improves the accuracy of the measuring device. Accurate measuring
improves product quality.
an instrument may vary from product to product but the process itself generally
involves using the piece of equipment to test samples of one or more values
also known as calibrators. When the results are found they are used to
establish a relationship between the measurement technique used by the
instrument and the known values.
Manufacturer’s specified tolerance
Consistency with similar instruments at your facility
Capability of available test equipment
Requirements of the process
tolerances should be determined from a combination of factors. These factors
Tolerance is the permissible deviation from a specified value; may
be expressed in measurement units, percent of span, or percent of reading.
is the degree of closeness of measurements of a quantity to its actual true
Precision is the degree to which repeated measurements under
unchanged conditions show the same result
There are two main characteristics
that will be needed when calibrating an instrument. These are Precision and
Instrument calibration is intended
to eliminate or reduce bias in an instrument’s readings over a range for
Calibration refers to the act of
evaluating and adjusting the precision and accuracy of measurement equipment.
company also require a report in which you describe the principles and need for
the calibration of an item of electronic test equipment.
Setting Resolution – 0.1dB
(or 0.01?V to 1mV) by direct keyboard entry, or in user-set increments of 0.1dB
to 100dB (or 0.01?V to 100mV)
Accuracy – Better than ± 2dBm
Frequency Range – 10MHz
+/- 1 ppm over 15°C to
30°C; +/- 2 ppm over 5°C to 40°C
Level Range – -110dBm
to +7dBm amplitude, 0.1dB steps
Full remote control through RS232, USB, LAN and GPIB
Storage for 12 generator set-ups and 16 sweep lists
User compensation tables for specific test set-ups
Fast stepping sweep with dwell times down to 10ms
Locking to external frequency standard
0MHz to 6000MHz frequency range
Generates different electrical waveforms over wide range of frequencies
An oscilloscope’s primary function is to provide a graph of
a signal’s voltage over time. This is useful for measuring such things as clock
frequencies, duty cycles of pulse-width-modulated signals, propagation delay,
or signal rise and fall times. It can also alert you to the presence of
glitches in your logic or bouncing switches.
Frequency range – 50 to 400Hz (Phase rotation test frequency, 45 to
Measuring range – 0 to 400K?
Voltage range – 100 to 690V AC
LCD resolution – 1V ±3%, 8 digits
LED resolution – 12, 24, 50, 120, 230, 400, 690V
Auto power on – less than 12V AD/DC
Optical and Acoustic indication
Voltage display – 12 to 690V AC/DC
Fully operational voltage indication even when batteries and discharge
Fully compliant with GS38
Phase rotation test system
Test continuity – Current
Test AC/DC voltage
A logic probe is a hand-held test probe used for analysing
and troubleshooting the logical states of a digital circuit.
Reverse power protection prevents signals traveling in the wrong
direction from damaging the source.
An on-board reference is a source of information, usually
referring to the clock, which supplies timing information.
Operation features to consider include on-board reference,
on-board oscillator, reverse power protection, and battery power.
The frequency range specifies the range of output frequencies
the generator can produce. The frequency resolution is the smallest frequency
increment the generator can produce. The generator’s internal clock determines
the frequency accuracy. It is a measure of how accurately the source frequency
can be set.
The maximum input channels refer to the maximum number of all
analogue input channels, general and specific types.
Description Function Generator, 4 MHz,
DC Offset Voltage± 10 V
Square Wave Symmetry? 2% (1 Hz to 100 kHz)
Impedance± 2% (50 ?)
Attenuator± 2% – 20 dB
Amplitude0.1 to 10 Vp-p (50 ? load)
Sine Wave Distortion