2, or if the difference between the two average

opacity values is less than 2 percent opacity. To conduct this demonstration, measure the opacities at the two locations or paths for a minimum period of 2 hours and compare the results. The opacities of the two locations or paths may be measured at different times, but must be measured at the same process operating conditions. Alternative procedures for determining acceptable locations may be used if approved by the Administrator. Insertillus.0021 Insert illus. 0 022 Insert illus. 0 023 Pt. 60, App. B, Spec. 1 5. Design and Performance Specifications 5.1 Design Specifications. The CEMS for opacity shall comply with the following design specifications: 5.1.1 Peak and Mean Spectral Responses. The peak and mean spectral responses must occur between 500 nm and 600 nm. The response at any wavelength below 400 nm or above 700 nm shall be less than 10 percent of the peak spectral response. 5.1.2 Angle of View. The total angle of view shall be no greater than 5 degrees. 5.1.3 Angle of Projection. The total angle of projection shall be no greater than 5 degrees. 5.1.4 Optical Alignment Sight. Each analyzer must provide some method for visually determining that the instrument is optically aligned. The method provided must be capable of indicating that the unit is misaligned when an error of +2 percent opacity occurs due to misalignment at a monitor path length of 8 meters. Instruments that are capable of providing an absolute zero check while in operation on a stack or duct with effluent present, and while maintaining the same optical alignment during measurement and calibration, need not meet this requirement (e.g., some "zero pipe" units). 5.1.5 Simulated Zero and Upscale Calibration System. Each analyzer must include a calibration system for simulating a zero (or no greater than 10 percent) opacity and an upscale opacity value for the purpose of performing periodic checks of the transmissometer calibration while on an operating stack or duct. This calibration system will provide, as a minimum, a system check of the analyzer internal optics and all electronic circuitry including the lamp and photodetector assembly. 5.1.6 Access to External Optics. Each analyzer must provide a means of access to the optical surfaces exposed to the effluent stream in order to permit the surfaces to be cleaned without requiring removal of the unit from the source mounting or without requiring optical realignment of the unit. 5.1.7 Automatic Zero Compensation Indicator. If the CEMS has a feature that provides automatic zero compensation for dirt accumulation on exposed optical surfaces, the system must also provide some means of indicating when a compensation of 4 percent opacity has been exceeded. This indicator shall be at a location accessible to the operator (e.g., the data output terminal). During the operational test period, the system must provide some means (manual or automated) for determining the actual amount of zero compensation at the specified 24-hour intervals so that the actual 24-hour zero drift can be determined (see Section 7.4.1). 5.1.8 Slotted Tube. For transmissometers that use slotted tubes, the length of the slotted portion(s) must be equal to or greater than 90 percent of the effluent path length (distance between duct or stack walls). The slotted tube must be of sufficient size and orientation so as not to interfere with the free flow of effluent through the cntire optical volume of the transmissometer photodetector. The manufacturer must also show that the transmissometer minimizes light reflections. As a minimum, this demonstration shall consist of laboratory operation of the transmissometer both with and without the slotted tube in position. Should the operator desire to use a slotted tube design with a slotted portion equal to or less than 90 percent of the monitor path length, the operator must demonstrate to the Administrator that acceptable results can be obtained. As a minimum demonstration, the effluent opacity shall be measured using both the slotted tube instrument and another instrument meeting the requirement of this specification but not of the slotted tube design. The measurements must be made at the same location and at the same process operating conditions for a minimum period of 2 hours with each instrument. The shorter slotted tube may be used if the average opacity measured is equivalent to the opacity measured by the nonslotted tube design. The average opacity measured is equivalent if it is within the opacity range defined by the average opacity value +10 percent measured by the nonslotted tube design, or if the difference between the average opacities is less than 2 percent opacity. 5.1.9 External Calibration Filter Access (optional). Provisions in the design of the transmissometer to accommodate an external calibration filter assembly are recommended An adequate design would permit occasional use of external (i.e., not intrinsic to the instrument) neutral density filters to assess monitor operation. 5.2 Performance Specifications. The opacity CEMS specifications are listed in Table 1-1. 6. Design Specifications Verification Procedure These procedures will not apply to all instrument designs and will require modification in some cases; all procedural modifications are subject to the approval of the Administrator. Test each analyzer for conformance with the design specifications of Sections 5.1.1-5.1.4, or obtain a certificate of conformance from the analyzer manufacturer as follows: 6.1 Spectral Response. Obtain detector response, lamp emissivity, and filter transmittance data for the components used in the measurement system from their respective manufacturers. and develop the effective spectral response curve of the transmissometer. Then determine and report the peak spectral response wavelength, the mean spectral response wavelength, and the maximum response at any wavelength below 400 mm and above 700 nm expressed as a percentage of the peak response. Alternatively, conduct a laboratory measurement of the instrument's spectral response curve. The procedures of this laboratory evaluation are subject to approval of the Administrator. TABLE 1-1-PERFORMANCE SPECIFICATIONS Expressed as the sum of the absolute value of the mean and the absolute value of the confidence coefficient. During the conditioning and operational test periods, the CEMS must not require any corrective maintenance, repair, replacement, or adjustment other than that clearly specified as routine and required in the operation and maintenance manuals. 6.2 Angle of View. Set up the receiver as specified by the manufacturer's written instructions. Draw an are with radius of 3 meters in the horizontal direction. Using a small (less than 3 centimeters) nondirectional light source. measure the receiver response at 5-centimeter intervals on the are for 30 centimeters on either side of the Parameter Specifications 1. Calibration BITOR <3 percent opacity. 2. Response time s10 seconds. 3. Conditioning period ≤168 hours. 4. Operational test period $168 hours. 5. Zero drift (24-hour)* 52 percent opacity. 6. Calibration drift (24-hour) <2 percent opacity. 7. Data recorder resolution <0.5 percent opacity. Pt. 60, App. B, Spec. 1 detector centerline. Repeat the test in the vertical direction. Then for both the horizontal and vertical directions, calculate the response of the receiver as a function of viewing angle (26 centimeters of are with a radius of 3 meters equals 5 degrees). report relative angle of view curves, and determine and report the angle of view. 6.3 Angle of Projection. Set up the projector as specified by the manufacturer's written instructions. Draw an are with a radius of 3 meters in the horizontal direction. Using a small (less than 3 centimeters) photoelectric light detector, measure the light intensity at 5-centimeter intervals on the are for 30 centimeters on either side of the light source centerline of projection. Repeat the test in the vertical direction. Then for both the horizontal and vertical directions, calculate the response of the photoelectric detector as a function of the projection angle (26 centimeters of are with a radius of 3 meters equals 5 degrees). report the relative angle of projection curves, and determine and report the angle of projection. 6.4 Optical Alignment Sight. In the laboratory set the instrument up as specified by the manufacturer's written instructions for a monitor path length of 8 meters. Align, zero, and span the instrument. Insert an attenuator of 10 percent (nominal opacity) into the instrument path length. Slowly misalign the projector unit by rotating it until a positive or negative shift of 2 percent opacity is obtained by the data recorder. Then, following the manufacturer's written instructions, check the alignment. The alignment procedure must indicate that the instrument is misaligned. Repeat this test for lateral misaligmment of the projector. Realign the instrument and follow the same procedure for checking misalignment of the receiver or retroreflector unit (lateral misalignment only). 6.5 Manufacturer's Certificate of Conformance (alternative to above). Obtain from the manufacturer a certificate of conformance stating that the first analyzer randomly sampled from each month's production was tested according to Sections 6.1 through 6.4 and satisfactorily met all requirements of Section 5 of this specification. If any of the requirements were not met, the certificate must state that the entire month's analyzer production was resampled according to the military standard 105D sampling procedure (MIL-STD-105D) inspection level II: was retested for each of the applicable requirements under Section 5 of this specification: and was determined to be acceptable under MIL-STD-105D procedures, acceptable quality level 1.0. The certificate of conformance must include the results of each test performed for the analyzer(s) sampled during the month the analyzer being installed was produced. 7. Performance Specification Verification Procedure Test each CEMS that conforms to the design specifications (Section 5.1) using the following procedures to determine conformance with the specifications of Table 1- 1. These tests are to be performed using the data recording system to be employed during monitoring. Prior approval from the Administrator is required if different data recording systems are used during the performance test and monitoring. 7.1 Preliminary Adjustments and Tests. Before installing the system on the stack, perform these steps or tests at the affected facility or in the manufacturer's laboratory. 7.1.1 Equipment Preparation. Set up and calibrate the CEMS for the monitor path length to be used in the installation as specified by the manufacturer's written instructions. For this specification, the mounting distance between the transmitter and receiver/reflector unit at the source must be measured prior to performing the calibrations (do not use distances from engineering drawings). If the CEMS has automatic path length adjustment, follow the manufacturer's instructions to adjust the signal output from the analyzer in order to yield results based on the emission outlet path length. Set the instrument and data recording system ranges so that maximum instrument output is within the span range specified in the applicable subpart. Align the instrument so that maximum system response is obtained during a zero (or upscale) check performed across the simulated monitor path length. As part of this alignment. include rotating the reflector unit (detector unit for single pass instruments) on its axis until the point of maximum instrument response is obtained. Follow the manufacturer's instructions to zero and span the instrument. Perform the zero alignment adjustment by balancing the response of the CEMS so that the simulated zero check coincides with the actual zero check performed across the simulated monitor path length. At this time. measure and record the indicated upscale calibration value. The calibration value reading must be within the required opacity range (Section 3.3). 7.1.2 Calibration Attenuator Selection. Based on the span value specified in the applicable subpart, select a minimum of three calibration attenuators (low, mid, and high range) using Table 1-2. If the system is operating with automatic path length compensation, calculate the attenuator values required to obtain a system response equivalent to the applicable values shown in Table 1-2; use Equation 1-1 for the conversion. A series of filters with nominal optical density (opacity) values of 0.1(20). 0.2(37), 0.3(50), 0.4(60), 0.5(68). 0.6(75), 0.7(80), 0.8(84), 0.9(88), and 1.0(90) are commercially available. Within this limitation of filter availability. select the calibration attenuators having the values given in Table 1-2 or having values closest to those calculated by Equation 1-1. D₁=D₂ (L₁/L₂) Eq. I-I TABLE 1-2-REQUIRED CALIBRATION ATTENUATOR VALUES (NOMINAL) Calibrated attenuator optical density Span value (percent (equivatent opacity in parenthesis)- opacity) D2 Low-range Mid-range High-range 40 0.05 (11) 0.1 (20) 0.2 (37) 50 0.1 (20) 0.2 (37) 0.3 (50) 60 0.1 (20) 0.2 (37) 0.3 (50) 70 0.1 (20) 0.3 (50) 0.4 (60) 80 0.1 (20) 0.3 (50) 0.6 (75) 90 0.1 (20) 0.4 (60) 0.7 (80) 100 0.1 (20) 0.4 (60) 0.9 (87.5) Where: D1=Nominal optical density value of required mid, low, or high range calibration attenuators. D₂=Desired attenuator optical density output value from Table 1-2 at the span required by the applicable subpart. Pt. 60, App. B, Spec. 1 L₁=Monitor path length. L₂=Emission outlet path length. 7.1.3 Attenuator Calibration. Select a laboratory calibration spectrophotometer meeting the specifications of