Exam 2 Flashcards
(24 cards)
The higher the gage factor for any strain gage material
The higher the strain gage sensitivity
The frequency response of a bonded strain gage is limited by the dynamic properties it mounts and supporting material
True
The venturi Flow meter is the least accurate flow meter because is has the highest head loss when compared to other obstruction flowmeters (True/False)
False
Discuss how the strain gage sensitivity to temperature changes can be reduced in a strain gage measuring set-up
The following flowmeter operation depends on a force balance between flow related
forces such as drag force and buoyancy force.
Rotameter
two capacitance in parallel
C1+C2
Two Capacitance in Series
((1/C1)+(1/C2))^-1
Two resistors in series
R1+R2
Two resistors in Parallel
((1/R1)+(1/R2))^-1
Discuss the operating principles of obstruction flowmeters
What is the different between a paddle-wheel flowmeter and a rotor flowmeter?
In a vortex flowmeter a pair of electrodes are attached to the pipe diametrically
opposite to each other to detect the vortex shedding frequency downstream from the bluff
body.
False
A single strain gauge mounted parallel to the hoop direction on a pressurized cylinder
is sufficient to give accurate measurement of the hoop strain.
False
The volume flow rate is linearly proportional to the pressure differential across the
flow meter
False
For maximum power consumption it is recommended that the impedance of the
source by at least 10 times less than the impedance of the load.
False
The following type of strain gage has the greatest gage factor:
Semiconductor
Discuss the operating principle of a bimetallic temperature sensor.
Using mercury instead of using alcohol as the measuring liquid in a thermometer
allows for higher temperature measurement range.
True
What are the major three differences between a thermometer and a thermistor?
One of the following sensors may have a negative sensitivity:
Thermistor
A strain gauge can be made from
-Wire
-Metal Foil
-Semiconductors
Lead (wire) compensation is implemented in a strain gage set-up to compensate for
the influence of added resistance of long wires in the set up.
True
Thermocouple
A temperature measuring instrument that is a junction of two different metals.
-Sensitivity(ouput/input) (EMF/deltaT)
-A change in temp generates EMF
RTD (Resistance Temperature Detector)
-Typically Made of Platinum
-A temperature measuring instrument that a delta Resistance is produced because of a change in temperature
