EPA lab upgrades test capability: Horiba to help modernize five test sites at vehicle and emissions lab

With phase-in dates for emission standards mandated by the 1990 Clean Air Act Amendments looming, the U.S. EPA will soon enhance its capabilities to conduct low-level gaseous and particulate emissions testing at its National Vehicle and Fuel Emissions Laboratory (NVFEL) in Arm Arbor, Mich. Driven by the need to test Tier 2 vehicles, Tier 2 and 3 nonroad engines, and 2007-compliant heavy-duty on-road engines, EPA recently awarded contracts to global emission test-system supplier Horiba Instruments to equip five test sites at NVFEL.

Targets for the comprehensive modernization program include two light-duty chassis sites, one medium/light-duty chassis site and two heavy-duty engine sites. (See related chart for summary of equipment).

"The projects to upgrade EPA's emissions testing capabilities in support of the Tier 2 light-duty and 2007 heavy-duty standards are clearly important for Horiba, but also significant for the entire industry," according to Carl Squire, Horiba's director of sales & marketing. "Horiba has made a considerable investment in measurement technology and the contracts with EPA reaffirm our leadership position within the industry Here is a brief overview of each of the NVFEL test sites:

Tier 2 Automotive--Perhaps the most significant feature of Tier 2, beyond the emission reductions relative in Tier 1, is its extended applicability. One set of standards will apply to cars, light-duty trucks, and medium-duty passenger vehicles such as SUVs regardless of the fuel they use--gasoline, diesel, oxygenated fuels, alcohol fuels, or gaseous fuels. EPA's new test site, designated D329, will be equipped to test any type of vehicle that is subject to Tier 2 regulations, while existing sites D005 and D002 will be dedicated to Tier 2 testing of light-duty cars and trucks fueled with gasoline.

All-Purpose Test Site--Site D329 will support testing of front-, rear-, four-and all-wheel drive light--duty and medium-duty vehicles, including those with advanced powertrain technology such as regenerative braking. To accommodate the wide variety of vehicles, Horiba will supply an ECDM-48M 4WD chassis dynamometer with up to 14,000 lb. of inertia simulation. The ECDM family of chassis dynamometers is manufactured for Horiba by MAFIA GmbH of Haldenwang, Germany.

Two MEXA-7000 analytical systems--one for diesel and one for gasoline--equipped with Horiba's advanced low emission analyzers will measure ultra-low levels of CO, THC, C[H.sub.4], and N[O.sub.x] as well as C[O.sub.2]. The THC, C[H.sub.4], and N[O.sub.x] analyzers for gasoline testing offer scalable dual ranges from 1 to 50 and 10 to 500 ppm C, while CO is scalable from 10 to 500 ppm. The diesel MEXA system includes a heated oven with THe, C[H.sub.4] and vacuum N[O.sub.x] analyzers. Both systems will provide bag and continuous dilute measurement capability. A photoacoustic spectroscopy infrared detector will be mounted in the MEXA-7000 cabinet and be incorporated into the MEXA7000 sample handling system for alternative fuels analysis. In addition, a stand-alone MEXA-1110FRF fast-response FID will allow EPA to confirm BMD response time.

The sampling system design for site D329 will support vehicles running on any fuel with a combination diesel/ gasoline constant volume sampler (CVS), a bag mini-diluter (BMD), ultra-sonic direct exhaust flowmeter and a particulate sampling system. The design permits both the BMD and CVS to be used simultaneously to allow direct correlation of emission results generated by the two methods, Horiba said.

To meet the flexibility requirements of site D329, the CVS will include two separate dilution tunnels and remote mixing tees for gasoline and diesel sample collection. Mounted on an overhead rail system, the diesel tunnel and mixing tee can easily be positioned near the vehicle for testing or moved to the side when not in use. The gasoline tunnel located on a cart--can be mounted in place of the diesel tunnel when needed. The remote mixing tees include a smooth approach orifice (SAO) for measuring dilution airflow so that tailpipe exhaust volume can be calculated by subtracting the dilution airflow rate from the CVS bulkstream flow rate.

The CVS exhaust sampler provides 15 selectable bulkstream flow rates up to 1800 scfm using four critical flow venturis. Twelve bags--four ambient, four diesel, one "dirty" gasoline and three "clean" ,gasoline--with dedicated "clean" and "dirty" sample lines, assure accurate measurements by preventing higher concentration samples from contaminating the "clean" line, the company said.