49 CFR § 572.44 - Instrumentation and test conditions.

§ 572.44 Instrumentation and test conditions.

(a) The test probe used for lateral thoracic and pelvis impact tests is a 6 inch diameter cylinder that weighs 51.5 pounds including instrumentation. Its impacting end has a flat right angle face that is rigid and has an edge radius of 0.5 inches.

(b) Three accelerometers are mounted in the thorax for measurement of lateral accelerations with each accelerometer's sensitive axis aligned to be closely perpendicular to the thorax's midsagittal plane. The accelerometers are mounted in the following locations:

(1) One accelerometer is mounted on the thorax to lumbar adaptor (SID-005 revision F, dated May 18, 1994, incorporated by reference; see § 572.40) with seismic mass center located 0.5 inches toward the impact side, 0.1 inches upward and 1.86 inches rearward from the reference point shown in Figure 30 in appendix A to subpart F of part 572. Maximum permissible variation of the seismic location must not exceed 0.2 inches spherical radius.

(2) Two accelerometers are mounted, one on the top and the other at the bottom part of the Rib Bar (SID-024) on the struck side. Their seismic mass centers are at any distance up to .4 inches from a point on the Rib Bar surface located on its longitudinal center line .75 inches from the top for the top accelerometer and .75 inches from the bottom, for the bottom accelerometer.

(c) One accelerometer is mounted in the pelvis for measurement of the lateral acceleration with its sensitive axis perpendicular to the pelvic midsagittal plane. The accelerometer is mounted on the rear wall of the instrumentation cavity of the pelvis (SID-087 revision H, dated May 18, 1994, incorporated by reference; see § 572.40). The accelerometer's seismic mass with respect to the mounting bolt center line is 0.9 inches up, 0.7 inches to the left for left side impact and 0.03 inches to the left for right side impact, and 0.5 inches rearward from the rear wall mounting surface as shown in Figure 31 in appendix A to subpart F of part 572. Maximum permissible variation of the seismic location must not exceed 0.2 inches spherical radius.

(d) Instrumentation and sensors used must conform to the SAE J-211 (1980) recommended practice requirements (incorporated by reference; see § 572.40). The outputs of the accelerometers installed in the dummy are then processed with the software for the Finite Impulse Response (FIR) filter (FIR 100 software). The FORTRAN program for this FIR 100 software (FIR100 Filter Program, Version 1.0, July 16, 1990) is incorporated by reference in this part (see § 572.40). The data are processed in the following manner:

(1) Analog data recorded in accordance with SAE J-211 (1980) recommended practice channel class 1000 specification.

(2) Filter the data with a 300 Hz, SAE Class 180 filter;

(3) Subsample the data to a 1600 Hz sampling rate;

(4) Remove the bias from the subsampled data, and

(5) Filter the data with the FIR100 Filter Program (Version 1.0, July 16, 1990), which has the following characteristics -

(i) Passband frequency, 100 Hz.

(ii) Stopband frequency, 189 Hz.

(iii) Stopband gain, −50 db.

(iv) Passband ripple, 0.0225 db.

(e) The mountings for the spine, rib and pelvis accelerometers shall have no resonance frequency within a range of 3 times the frequency range of the applicable channel class.

(f) Limb joints of the test dummy are set at the force between 1-2 g's, which just supports the limbs' weight when the limbs are extended horizontally forward. The force required to move a limb segment does not exceed 2 g's throughout the range of limb motion.

(g) Performance tests are conducted at any temperature from 66 °F to 78 °F and at any relative humidity from 10 percent to 70 percent after exposure of the dummy to these conditions for a period of not less than 4 hours.

(h) For the performance of tests specified in §§ 572.42 and 572.43, the dummy is positioned as follows:

(1) The dummy is placed on a flat, rigid, clean, dry, horizontal smooth aluminum surface whose length and width dimensions are not less than 16 inches, so that the dummy's midsagittal plane is vertical and centered on the test surface. The dummy's torso is positioned to meet the requirements of § 572.42 and § 572.43. The seating surface is without the back support and the test dummy is positioned so that the dummy's midsagittal plane is vertical and centered on the seat surface.

(2) The legs are positioned so that their centerlines are in planes parallel to the midsagittal plane.

(3) Performance pre-tests of the assembled dummy are separated in time by a period of not less than 20 minutes unless otherwise specified.

(4) Surfaces of the dummy components are not painted except as specified in this part or in drawings subtended by this part.

[55 FR 45766, Oct. 30, 1990, as amended at 56 FR 47011, Sept. 17, 1991; 59 FR 52091, Oct. 14, 1994]