Weighing System Installation & Verification Flashcards
7 cards from real CWT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Weighing System Installation & Verification flashcards as text
What is the primary function of a check rod (stay rod) in a hopper or tank scale installation?
Answer: To prevent lateral movement while allowing vertical load measurement
Check rods constrain horizontal and lateral movement of the vessel without interfering with the vertical forces the load cells must measure.
Which type of fastener is recommended when mounting load cells in environments subject to vibration?
Answer: Nylon insert lock nuts (Nylock) or prevailing torque fasteners
Nylon insert lock nuts (Nylock) and other prevailing torque fasteners resist loosening caused by repeated vibration, maintaining proper load cell clamping force.
What is the typical rated output of a standard strain-gauge load cell at full capacity?
Answer: 2–3 mV/V
Standard strain-gauge load cells produce a millivolt-level differential signal, typically rated at 2–3 mV/V of excitation voltage at full rated capacity.
During weighing system installation, which environmental condition most critically affects measurement accuracy?
Answer: Temperature stability and thermal gradients across the structure
Thermal gradients cause differential expansion of the weighing structure and shift load cell zero and span, making temperature stability the most critical environmental factor.
What tool is used to verify that a platform scale is properly leveled during installation?
Answer: Spirit level or precision machinist's level
A spirit level or precision machinist's level is placed on the platform surface to confirm it is within the allowable tilt tolerance before calibration begins.
Why is shielded cable required for load cell signal wiring in most installations?
Answer: To prevent electromagnetic interference (EMI) from corrupting the low-level signal
Load cell signals are in the millivolt range and extremely susceptible to EMI; shielded cable with the shield grounded at one end prevents induced noise from corrupting the measurement.
When installing a truck scale, which foundation characteristic is most critical for long-term weighing accuracy?
Answer: Concrete compressive strength and uniform bearing capacity
Adequate concrete compressive strength and uniform bearing capacity prevent differential settling that would shift load distribution among load cells and cause persistent errors.