IMSA Signal Inspector flashcards
IMSA Signal Inspector · Build recall with a focused review session.
31 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Conflict monitor test
- A test that places the malfunction management unit in test mode to verify it senses conflicting green outputs and latches a fault, driving the signal to flash.
- Loop inductance check
- A field measurement of the inductive loop's inductance and resistance using an ohmmeter or loop tester, confirming values fall within the detector manufacturer's specified range.
- Pedestrian clearance interval
- The time programmed for the flashing DON'T WALK or countdown display, calculated so a pedestrian can clear the intersection before the conflicting green begins.
- Ground resistance measurement
- A field test using a fall-of-potential or clamp-on tester to confirm the cabinet ground rod and bonding system meet the specified resistance value.
- Detection zone verification
- A field check confirming video or radar detection zones match the plan view, including stop-bar and setback dimensions and absence of occlusion.
- Timing chart comparison
- A check comparing the controller's programmed green, yellow, all-red, walk, and clearance intervals to the approved timing chart and coordination offsets.
- Accessible pedestrian signal check
- A field verification that the APS provides audible and vibrotactile output, activates on pushbutton, and matches the programmed walk and clearance timing.
- Punch list re-verification
- The process of re-inspecting and documenting correction of each deficiency before the signal is accepted and placed into service.
- NEMA TS 2 cabinet
- A cabinet standard using a Type 1 or Type 2 cabinet with a 170 or 2070 controller, an SDLC data link, and a malfunction management unit.
- ATC cabinet
- A cabinet built to the Advanced Transportation Controller standard (ATC 5201/5301), using an ATC controller with an Ethernet or SDLC backplane.
- Malfunction management unit
- The device in a NEMA TS 2 cabinet that monitors signal outputs for conflicts and faults, latching the signal to flash when a fault is detected.
- Conflict monitor unit
- The equivalent of the MMU in 170 and 2070 cabinets, monitoring field outputs and driving the signal to flash on a detected conflict or fault.
- Semi-actuated control
- A controller mode in which the mainline runs free and the side street is actuated by vehicle or pedestrian detection, commonly used at minor-street intersections.
- Flash transfer relay
- The cabinet relay that switches signal outputs to flashing operation on loss of power or a fault, typically flashing yellow mainline and red side street.
- SDLC data link
- The serial data link in NEMA TS 2 cabinets connecting the controller to the MMU, detector racks, and other auxiliary devices for monitoring and control.
- Controller firmware version
- The recorded software version loaded in the controller, documented during inspection to confirm the approved configuration and support future maintenance.
- Four-section signal head
- A signal head with red, yellow, green, and a protected left-turn arrow, used where a protected left-turn phase is provided for one approach.
- Twisted loop feeder
- The home-run conductor pair from an inductive loop, twisted at a minimum of three to four twists per foot to reduce electrical noise and crosstalk.
- Signal head mounting height
- The vertical distance from the roadway to the bottom of the signal head, typically 15 to 19 feet for span-wire and mast-arm installations.
- NEMA wiring color code
- The standard conductor colors for signal circuits: red for red display, yellow for yellow, green for green, white neutral, black hot, and green or bare ground.
- Backplate requirement
- A non-reflective plate mounted behind the signal lenses to improve visibility against bright backgrounds and reduce sun phantom, required per the plan.
- Detector loop saw-cut
- The pavement cut in which an inductive loop is installed and sealed with loop sealant, with loop size and turns determining the resulting inductance.
- Splice enclosure requirement
- A rule that all splices must be made in approved, accessible, waterproof enclosures; direct-buried splices are not permitted.
- Pushbutton mounting height
- The height of a pedestrian pushbutton above grade, typically 42 inches, to meet accessibility requirements and reachable by all users.
- Temporary traffic control plan
- An approved plan per MUTCD Part 6 covering advance warning, taper, buffer, and termination areas for work affecting a signalized intersection.
- Flagger certification
- The training and certification required for flaggers, who must wear high-visibility apparel and use stop/slow paddles to control traffic.
- Signal deactivation notice
- The requirement to notify the agency and emergency services before taking a signal out of service, with flaggers or temporary signals controlling the intersection.
- As-built documentation
- Final records of conduit, loop, pole, and cabinet locations, plus updated timing charts and cabinet wiring diagrams reflecting field conditions.
- Substantial completion
- The milestone at which all tests pass, punch-list items are corrected, and the agency issues written acceptance, typically starting the warranty period.
- Right-of-way permit
- The permit required before construction begins in the public right-of-way, with conditions that must be met throughout the work.
- Deficiency reporting
- The process of documenting and reporting safety hazards, utility damage, or nonconforming work to the agency and tracking corrective action to closure.