Rectifier and amplifier type of instruments are used and studies in the filed of instrumentation and Measurements as they provide authentic source to explore more ideas about the types and construction of such instruments

1. Department Of Electrical Engineering
Batch : 15 EL
Date : 13 December 2016

2. Subject : Instrumentation & Measurements
Assigned to : Mis Kalsoom Bhagat
By: Farhan Memon

3.  Rectifier type instruments are used for measurement of ac. voltages and
currents by employing a rectifier element, which converts a.c. to a
unidirectional d.c. and then using a meter responsive to d.c. to indicate
the value of rectified a.c.
 The indicating instrument is PMMC instrument, which uses a
d’Arsonval movement.
 This method is very attractive since PMMC instruments have a higher
sensitivity than the electrodynamometer or the moving iron
instruments.

4. A D.C. moving-coil meter can be used to measure A.C. voltage by putting a
diode or rectifier in the meter circuit.

5. Rectifier type instrument measures the alternating voltage and
current with the help of rectifying elements and permanent
magnet moving coil type of instruments. However the primary
function of rectifier type of instruments work as voltmeter. Now
one question must arises in our mind why we use rectifier type of
instruments widely in the industrial world though we have various
other AC voltmeter like electrodynamometer type instruments,
thermocouple type instruments etc? The answer to this question is
very simple and is written as follows.
1.Cost of electrodynamometer type of instruments is quite high
than rectifier type of instruments.
2.The thermocouple instruments are more sensitive than the
rectifier type of instruments.

6. Half Wave Rectifier Circuits of Rectifier Type Instruments

7. Full Wave Rectifier Circuits of Rectifier Type Instruments

9. 1.The accuracy of rectifier type instrument is about 5 percent under
normal operating condition.
2.The frequency range of operation can be extended to high value.
3.They have uniform scale on the meter.
4.They have low operating value of current and voltages.
5.The loading effect of an ac rectifier voltmeter in both the cases (i.e.
half wave diode rectifier and full wave diode rectifier) is high as
compared to the loading effects of DC voltmeters as the sensitivity of
the voltmeter either using in half wave or full wave rectification is less
than the sensitivity of DC voltmeters.
Advantages of Rectifier Type Instruments

10.  An instrument amplifier is an electronic device which converts the often
barely audible or purely electronic signal of a musical instrument into
an audible sound. An instrument amplifier is used with musical
instruments such as an electric guitar, an electric bass, electric organ,
synthesizers and drum machine to convert the signal from the pickup
(with guitars and other string instruments and some keyboards) or
other sound source (e.g, a synthesizer's signal) into an electronic signal
that has enough power, due to being routed through a power amplifier,
capable of driving one or more loudspeaker that can be heard by the
performers and audience.

11. Instrument amplifiers are available for specific instruments, including the
electric guitar, electric bass, electric/electronic keyboards, and acoustic
instruments such as the mandolin and banjo. Some amplifiers are designed
for specific styles of music, such as the "traditional"-style "tweed" guitar
amplifiers, such as the Fender Bassman used by blues and country music
musicians, and the Marshall amplifiers used by hard rock and heavy metal
bands.

12. Types
Guitar amplifiers
Bass
keyboard amplifier