Seat Reference Point
Definition - What does Seat Reference Point mean?
In ergonomic design, the seat reference point is used to identify the part of a chair, or other seating device, where the backrest and seat pan intersect. The seat reference point is used as a position from which measurements are calculated to determine the size and proportions of a seating device.
WorkplaceTesting explains Seat Reference Point
The seat reference point is a defined point at which the horizontal and vertical planes of a seat or chair intersect. The seat reference point is a point of interface between the object and its human user.
In furniture and seating design, the seat reference point may be further defined with regard to the particular item being crafted. For instance, the Society of Automotive Engineers (SAE) clarifies the seat reference point to be the measurement from the intersection of the compressed seat back and cushion. This means that the point at which a person actually sits as opposed to the intersection of two imaginary planes within the seat. The SAE also defines seating reference point (SgRP) to represent the seat reference point (SRP) for the 95th percentile occupant.
Most consumer vehicles are designed so that the seat will accommodate this 95th percentile driver when the seat is in its most rearward adjustment. In contrast, a neutral seat reference point (NSRP) is based on the needs of a 50th percentile occupant. A seat created using the neutral seat reference point, that cannot be adjusted, would be a tight fit for someone in the 95th percentile, and might require a person in the 5th percentile to use boosters.
Ergonomic seating design must carefully consider the end user and provide for adjustments that allow a range of individuals to make use of the object. In most instances, designers will use anthropometric data representing the 5th and 95th percentile of a selected population in order to ensure a seat will accommodate the maximum number of users.