3. Overview of handling procedures

An Anthropomorphic Test Device (ATD) is not a consumable that can be pulled from a shelf and bolted into a sled at will. A Hybrid III 5th-percentile female, 50th-percentile male, or 95th-percentile male is a calibrated precision instrument whose response corridors are only valid while its physical condition, instrumentation state, and configuration history remain within controlled limits. The handling procedures that surround these devices exist to preserve that validity. This section establishes the scope of those procedures, the safety obligations they impose, the documentation that makes an ATD's history auditable, and the end-to-end lifecycle that a device follows from the moment it arrives at a facility until it is placed in long-term storage.

Scope: What the Procedures Govern and What They Do Not

Handling procedures apply to every activity that can alter an ATD's mechanical state or its measurement chain. In practical terms this covers receipt and incoming inspection, lifting and transport within the facility, mounting to and removal from test fixtures, instrumentation installation and removal, calibration and verification, post-test inspection, repair and parts replacement, and storage. They also govern the environmental conditions under which the device is kept, because the polyurethane flesh and the rubber neck and lumbar elements are viscoelastic: their stiffness depends on temperature and on the time-history of loading.

The procedures do not replace the manufacturer's calibration and certification requirements, nor the test-specific setup instructions in the relevant regulation or protocol (for example, a frontal impact procedure specifying seat position, belt geometry, and joint torque settings). Handling procedures are the envelope around those tasks. A useful way to state the boundary is: if an action changes a joint torque, a sensor zero, a flesh dimension, or the device's thermal history, it is in scope and must be recorded.

Safety Obligations

Three distinct safety domains apply, and conflating them is a common source of incidents.

• Personnel safety. A fully instrumented 95th-percentile male ATD masses roughly 100 kg and is awkward to grasp; the torso is rigid and the limbs are limp. Manual lifting of an assembled device by two people is a back-injury risk. Use a dedicated ATD lift or a minimum of three trained handlers supporting the torso, pelvis, and legs, and never lift by the head, neck, arms, or any cable bundle.
• Device safety. The neck and lumbar spine are the most fragile assemblies. Dropping a device even a few centimetres onto a hard floor can introduce a permanent bend or a cracked load cell that will not be visible externally but will shift the response. Never allow the head to rest unsupported, and never set the device down on its back without a shaped cradle.
• Test-article and facility safety. ATDs are frequently handled in the same cell as pyrotechnic actuators, high-speed sleds, and overhead crane traffic. Establish a handling zone with the sled disarmed, the crane parked, and the device's location communicated to the test conductor before any movement begins.

Documentation: The Device History Record

Every ATD should carry a device history record (DHR) that travels with it or is unambiguously linked to its serial number. The DHR is what allows an engineer six months later to answer the question "was this load cell within calibration when the test was run?" A workable DHR contains, at minimum:

In practice the DHR is a combination of a paper or electronic logbook and the calibration certificates filed against the serial number. The critical discipline is contemporaneity: entries are made when the action happens, not reconstructed at the end of a test campaign.

The ATD Lifecycle from Receipt to Storage

The lifecycle is best understood as a sequence of state transitions, each with an entry condition, a set of actions, and an exit criterion that must be satisfied before the next state is entered. The figure below shows this as a state-and-transition diagram with the verification gate that governs each transition.

Receipt and Incoming Inspection

On arrival, the device is unpacked in a clean, level area with the shipping crate retained until inspection is complete. Record the serial number and compare it against the packing list and the DHR. Photograph all four sides and the head, neck, and pelvis before removing any protective wrapping. Then perform the incoming inspection: measure the key flesh dimensions against the manufacturer's drawing, check that each joint moves freely and that the specified torque can be set, and confirm sensor continuity with a bridge resistance check on each channel. A 350 Ω bridge reading of roughly 350 Ω ±1 Ω at the connector is a normal result; an open circuit or a reading near zero indicates a damaged cable or load cell and should be resolved before the device is accepted.

Staging and Environmental Conditioning

Before instrumentation and before any test, the device must reach thermal equilibrium with the test environment. The standard practice is to soak the ATD at the test cell temperature for a period specified by the procedure — commonly several hours for a full assembly — because the flesh stiffness and the neck response are temperature-sensitive. Staging is therefore not idle time; it is a controlled state with a recorded start time, ambient temperature, and humidity. A device that is brought in from a cold loading dock and tested the same hour will produce responses outside the certification corridors even if every sensor is perfectly calibrated.

Instrumentation, Calibration, and Test Use

Instrumentation installation follows the channel list in the DHR. Each sensor is mounted at its defined location, its serial number is entered against the channel, and the cabling is routed with service loops so that limb motion does not tension the leads. Calibration and verification then establish that the measurement chain is traceable: sensor zero is recorded, a shunt calibration confirms the gain, and the certificate is filed. Only after the verification gate is passed is the device released for mounting and test use. During test use the handling discipline continues — the device is positioned per the protocol, joint torques are set and recorded, and no ad-hoc adjustments are made without a corresponding DHR entry.

Post-Test Inspection, Repair, and Storage

After the test, inspect the device before it leaves the cell. Look for flesh tears, permanent set in the neck or lumbar, bent limbs, and cable damage, and compare post-test sensor zeros against pre-test values; a zero shift beyond the manufacturer's limit indicates possible overload. If a defect is found, the device moves to repair or replacement, followed by recalibration and re-verification before it can return to service. If damage exceeds repairable limits, the device is retired: it is tagged out of service, its DHR is closed and archived, and disposal follows the applicable procedure. A serviceable device returns to storage in a shaped cradle, covered to protect the flesh from light and dust, in a temperature-controlled area, with the storage location and environmental exposure entered in the DHR. That entry closes the loop and becomes the starting condition for the next receipt-to-storage cycle.