Model 8370 AccuBalance Manual
Contents
1. Switching On the Power The power ON OFF switch is located on the meter keypad of the ACCUBALANCE To turn the power on momentarily press the ON OFF switch The ACCUBALANCE will immediately light all display digits and sound the buzzer After a second the approximate percent of remaining battery life will be displayed If fresh new alkaline batteries are used the value will be near 100 percent Other batteries such as NiCd batteries may show a lower value even when they are fully charged Notice The percent power remaining will not be accurate for NiCd batteries because they do not discharge linearly with power use While the battery life is being displayed the ACCUBALANCE will automatically perform a series of self tests If an error is detected the display will show an error number Refer to Troubleshooting in Chapter 4 for interpretation of the error message If no errors are detected during start up the ACCUBALANCE will proceed to one of its two operating modes continuous reading mode or averaging mode As long as the batteries have not been removed or the DIP switch settings have not been changed the ACCUBALANCE will return to the mode it was in when it was last used Selecting Flow Direction The ACCUBALANCE is designed to accurately measure air flow in either direction through the hood For highest performance accuracy every ACCUBALANCE is calibrated with flow in each direction separately Therefore it is very i2. NO ACTION REGARDLESS OF FORM MAY BE BROUGHT AGAINST THE SELLER MORE THAN ONE YEAR AFTER THE CAUSE OF ACTION HAS ACCRUED The purchaser and all users are deemed to have accepted the terms of this LIMITATION OF WARRANTY AND LIABILITY which contains the complete and exclusive limited warranty of seller This LIMITATION OF WARRANTY AND LIABILITY may not be amended or modified nor may any of its terms be waived except by a writing signed by an authorized representative of seller Service Policy Knowing that inoperative or defective instruments are as detrimental to TSI as they are to our customers our service policy is designed to give prompt attention to any problems If any malfunction is discovered please contact your nearest sales office or representative or call TSI s Customer Service department at 651 490 2711 or 800 777 8356 Contents About this manual Introduction Chapters Setup Unpacking Parts Identification Keypad Display Preparing the Instrument for Use Display Units Installing the Batteries Start Up Continuous Reading Mode Averaging Mode Selecting Flow Direction Taking a Flow Measurement Turning the ACCUBALANCE Off Automatic Shut off Operations in More Detail Changing Hoods Switching On the Power Selecting Flow Direction Continuous Reading Mode Averaging Mode Selecting Flow Units Selecting the Time Constant Changing DIP Switch Settings Low Battery Warning Automatic Shut off Connecting the Opt
3. if an error message appears If no errors are found the ACCUBALANCE will automatically proceed to one of two measurement modes continuous reading mode or averaging mode Continuous Reading Mode In the continuous reading mode the measurement is updated on the display every second You can slow the update rate to once every two seconds by changing the setting of DIP Switch 7 For more details see Changing DIP Switch Settings in Chapter 2 The display continues to update until you press either the START HOLD switch on the keypad or the button on the right handle The current value will be held on the display along with the HOLD message To resume continuous readings press one of the START HOLD buttons again For more details about the continuous reading mode see Chapter 2 Averaging Mode In the averaging mode a time averaged reading is initiated each time you press the START HOLD switch on the keypad or the button on the right handle The time counts down from three seconds on the display After the countdown the average flow appears and remains on the display along with the AVERAGE message To initiate a new reading press one of the START HOLD buttons again You can select an Set Up 15 averaging time of six seconds by changing the setting of DIP Switch 6 See Changing DIP Switch Settings in Chapter 2 For more details on the averaging mode see Chapter 2 Selecting Flow Direction Each ACCUBALANCE is calibrated for supp
4. manifold should be kept in place during cleaning Do not apply excessive forces on the grid tubes of the manifold If any of the tubes are bent or damaged please contact TSI for repair information Calibration TSI recommends an annual calibration for the ACCUBALANCE For a nominal fee TSI will calibrate the unit and return it to you with a certificate of calibration and NIST traceability This annual checkup assures you of consistently accurate readings To calibrate the ACCUBALANCE please ship TSI the complete package that includes the meter the base the manifold and any fabrics used Everything should Maintenance 37 be packed carefully within the ACCUBALANCE carrying case and then inside a proper shipping box such as the original shipping box Ship directly to TSI Inc ATTN Customer Service 500 Cardigan Road Shoreview MN 55126 3996 38 Chapter 3 Chapter 4 Troubleshooting Table 5 lists the symptoms possible causes and recommended solutions for common problems encountered with the ACCUBALANCE If your symptom is not listed or if none of the solutions solves your problem please contact TSI Table 5 Troubleshooting the ACCUBALANCE Symptom No display LOW BATTERY on display Flashing 0 Flow is under range Possible Causes Unit not switched on Low or dead batteries Dirty battery contacts Battery holder not connected Low battery charge Dirty battery contacts Trying to read too low a f
5. and 14 7 psia 760 mmHg By contrast actual flow is the volumetric flow rate of air at local temperature and barometric pressure conditions It is common in ventilation test applications that standard flow is the desired measurement parameter The ACCUBALANCE automatically indicates standard flow readings There is therefore no need to apply a correction factor however if you wish to convert standard flow readings to actual flow readings you must apply an air density correction factor 14 7 4604 Tr Actual Flow Standard Flow IUPa IL 530 Par Your local barometric pressure in psia where j Ta Your air flow temperature in F Or 760 273 154 Tre Actual Flow Standard Flow LE 294 25 Par Your local barometric pressure in mmHg where 9 f Tue Your air flow temperature in C 41 Example 1 Suppose your air flow temperature is 55 F and you local barometric pressure is 13 5 psia and the standard flow indicated on the ACCUBALANCE is 200 standard CFM 14 7 460 55 Actual Flow 200 212 Actual CFM 13 5 530 Example 2 Suppose your air flow temperature is 25 C and your local barometric pressure is 730 mmHg and the standard flow indicated on the ACCUBALANCE is 100 standard 1 5 760 273 15 25 A Flow 100 105A ctual Flow aan is 05 Actual l s t 42 Appendix A Appendix B Back Pressure It is commonly known that a flow measuring hood may induce a back
6. factory set up to operate at the one second display rate You may change to a two second display rate by adjusting switch 7 under the battery cover see Changing DIP Switch Settings The flow sensor in the ACCUBALANCE is extremely fast and actually samples flow at a rate of 10 times per second Thus the values displayed in the one second mode represent an integration of 10 readings each Likewise the values displayed in the 2 second mode represent an integration of 20 readings each By selecting the slower 28 Chapter 2 2 second display rate you will therefore see less variation in the displayed values In the averaging mode you may choose between a three second and a six second averaging time period The ACCUBALANCE is shipped set up in the three second averaging mode You can change this by changing the setting of switch 6 in the battery compartment see Changing DIP Switch Settings Changing DIP Switch Settings You can change flow units and time constants by adjusting the settings of the DIP switches located inside the battery compartment To gain access to the DIP switches first turn off the ACCUBALANCE and lay down the instrument with the electronic meter facing down as shown in Figure 12 Operations in More Detail 29 Figure 12 ACCUBALANCE lying face down Remove the battery compartment cover by pulling up on the two latches You will see the switches numbered 1 through 8 in the corner of the battery compartment You
7. ft 610 mm x 1220 mm 800591 1 ft x 4 ft 305 mm x 1220 mm 800592 3 ft x 3 ft 915 mm x 915 mm 800593 1 ft x 5 ft 305 mm x 1525 mm 800594 35 Frame Kit 1081263 It is recommended that you purchase a frame kit whenever you purchase a hood other than the 2 ft x 2 ft size The frame kit contains all extra frame tubing and connectors required to build frames for the various size hoods The frame kit consists of the following parts 4 pieces 1 foot frame tubing 2 pieces 2 foot frame tubing 6 pieces straight tubing connectors Meter The ACCUBALANCE has a built in electronic flow meter Do not try to detach the meter from the base The ACCUBALANCE should be used and stored within the specified temperature range 32 140 F 0 60 C The meter case display screen and membrane switch can be cleaned using a damp cloth with mild detergent solution Do not immerse the meter in water Wipe the meter dry before use Manifold If you notice that a tube in the flow sensing manifold has become disengaged from its rubber holder as shown in Figure 14 work the tube end back into the holder The accuracy of the ACCUBALANCE is not affected by having one or two tubes out of their holders however it is a good practice to keep the tubes properly in place 36 Chapter 3 Figure 14 Flow Sensing Tube Out of Place If you observe the flow sensing taps of the manifold becoming clogged with dust or other material clean them with a damp cloth The
8. may wish to remove or tilt up the battery pack to allow easier access to the switches as shown in Figure 13 30 Chapter 2 Figure 13 Location of DIP Switches You may change the switch settings using the tip of a ball point pen pencil compass small screwdriver or other small pointed object Refer to Table 2 for switch settings Operations in More Detail 31 Table 2 DIP Switch Settings Switch Number Setting Function 1 Leave in OFF position 3 4 3 OFF 4 OFF Flow units CFM OFF 4 ON Flow units 1 s__ 3 ON 4 ON Flow units m hr Leave in OFF position for Rev A thru Rev M Leave in ON position for Rev N and later OFF 1 second display update rate in Continuous Reading Mode ON 2 second display update rate in Continuous Reading Mode See the serial number sticker on the unit to find the Rev level of your ACCUBALANCE unit Low Battery Warning When a battery power is running low the message LOW BATTERY will appear on the display NOTE The readings given by the ACCUBALANCE when LOW BATTERY is displayed are still valid Before the battery power gets so low that valid flow measurements are not possible the ACCUBALANCE will shut itself off When the LOW BATTERY message appears you usually have at least a half hour of running time before the power gets so low that the ACCUBALANCE would automatically turn itself off If the optional printer is connected the message LOW BATTERY is printed jus
9. mount in the ACCUBALANCE base Bend the pole slightly to guide the other end into the corresponding support pole cup located on the underside of the frame near the white mark on the fabric Operations in More Detail 21 Figure 8 Installing a support pole 8 Repeat step 7 until all four support poles are installed 9 Now that the hood is assembled and the fabric is stretched tight it is a good practice to check the rubber gasket around the top edge of the ACCUBALANCE fabric In order to achieve a good straight alignment of the rubber gasket along the top of the frame structure you may need to peel back and re attach small portions of the Velcro surfaces 10 Finally at the corners tuck the straight rubber gasket flaps under the edges cut at an angle This will create a virtually leak free soft pliant seal 22 Chapter 2 1 ft x 4 ft Hood To assemble and attach the 1 ft x 4 ft hood carefully follow these 10 steps 1 Build the 1 ft x 4 ft frame structure as shown in Figure 9 using four 2 ft aluminum frame tubing pieces two 1 ft aluminum frame tubing pieces four right angle tubing connectors and two straight tubing connectors Remember to construct the frame so that all Velcro surfaces face in toward the center of the structure Notice Make sure that all support pole cups in the aluminum frame tubing pieces are facing downward Figure 9 Assembled 1 ft x 4 ft frame 2 Unfold the 1 ft x 4 ft fabric hood
10. ALANCE will read slightly lower than the true flow At 80 CFM 40 1 s for example the ACCUBALANCE will read low by 2 CFM 1 1 s Therefore you may wish to add 2 CFM 1 1 s when the indicated flow is 80 CFM 40 1 s 3 CFM 1 5 I s at 50 CFM 25 1 s and 4 5 CFM 21 s at 30 CFM 15 1 5 to obtain a more accurate reading No correction is required at flows greater than 100 CFM 50 l s Notice This correction factor is necessary only in the Return Mode The Supply Mode does not require a correction 47 48 Appendix D Appendix E Specifications Flow Range Accuracy Operating Temperature Range Weight using 24 in x 24 in Hood Hood Sizes Available Power Battery Life Carrying Case RS 232C Output 30 2 000 CFM 15 1 000 I s 50 3 500 m hr 5 rdg 5 CFM 2 4 Is 8 5 m hr 32 140 F 0 60 C 7 Ib 6 oz 3 4 kg 24 in x 24 in 610 mm x 610 mm 24 in x 48 in 610 mm x 1220 mm 12 in x 48 in 305 mm x 1220 mm 12 in x 60 in 305 mm x 1525 mm 36 in x 36 in 915 mm x 915 mm 4 C size batteries 4 alkaline batteries provided At least 40 hours of continuous use 26 in x 26 in x 7 in 660 mm x 660 mm x 180 mm ASCII Character codes 1200 Baud No parity 8 data bits 1 stop bit No handshaking These specifications are subject to change without notice 49 50 Appendix E
11. Continue with steps 3 through 10 beginning on page 20 1 ft x 5 ft Hood To assemble and attach the 1 ft x 5 ft hood carefully follow these 10 steps Operations in More Detail 23 1 Build the 1 ft x 5 ft frame structure as shown in Figure 10 using four 2 ft aluminum frame tubing pieces two 1x tube connectors two 1 ft aluminum frame tubing pieces and four right angle tubing connectors Remember to construct the frame so that all Velcro surfaces face in toward the center of the structure Notice Make sure that all support pole cups in the aluminum frame tubing pieces are facing downward Figure 10 Assembled 1 ft x 5 ft frame 2 Unfold the 1 ft x 5 ft fabric hood Continue with steps 3 through 10 beginning on page 20 24 Chapter 2 3 ft x 3 ft Hood To assemble and attach the 3 ft x 3 ft hood carefully follow these 10 steps 1 Build the 3 ft x 3 ft frame structure as shown in Figure 11 using four 2 ft aluminum frame tubing pieces four 1 ft aluminum frame tubing pieces four right angle tubing connectors and four straight tubing connectors Remember to construct the frame so that all Velcro surfaces face in toward the center of the structure Notice Make sure that all support pole cups in the aluminum frame tubing pieces are facing downward Figure 11 Assembled 3 ft x 3 ft frame 2 Unfold the 3 ft x 3 ft fabric hood Continue with steps 3 through 10 beginning on page 20 Operations in More Detail 25
12. Model 8370 ACCUBALANCE Flow Measuring Hood Operation and Service Manual September 1998 P N 1980145 Rev B Model 8370 ACCUBALANCE Flow Measuring Hood Operation and Service Manual September 1998 P N 1980145 Rev B SHIP TO MAIL TO TSI Incorporated TSI Incorporated 500 Cardigan Road P O Box 64394 Shoreview MN 55126 St Paul MN 55164 U S INTERNATIONAL Sales amp Customer Service Sales amp Customer Service 800 777 8356 651 490 2711 1 651 490 2711 Fax Fax 651 490 2874 1 651 490 2874 Copyright TSI Incorporated Decmber 1996 All rights reserved Address TSI Incorporated 500 Cardigan Road P O Box 64394 St Paul MN 55164 USA Fax No 651 490 2874 Limitation of Warranty and Liability Seller warrants that this product under normal use and service as described in the operator s manual shall be free from defects in workmanship and material for a period of twenty four 24 months or the length of time specified in operator s manual from the date of shipment to the customer This limited warranty is subject to the following exclusions 1 Batteries hot wire or hot film sensors and certain other components when indicated in specifications are warranted for a period of 90 days from the date of shipment to the customer 2 With respect to any repair services rendered seller warrants that the parts repaired or replaced will be free from defects in workmanship and material under no
13. Service Manual 1980145 Four 2 ft frame tubings and four of the right angle connectors are shipped assembled inside the top of the hood fabric Table 1a List of components Model 8370 3 Qty Item Part No 1 Model 8370 base 1081388 1 2 ft x 2 ft 610 mm x 610 mm hood fabric 1307060 1 2 ft x 4 ft 610 mm x 1220 mm hood fabric 1801065 1 1 ft x 4 ft 305 mm x 1220 mm hood fabric 1801066 6 Frame support poles 1081390 6 2 ft 610 mm frame tubing 1081262 4 1 ft 305 mm frame tubing 1081260 6 Right angle tubing connectors 1081584 6 Straight tubing connectors 1302833 1 Battery holder 1081279 4 C size batteries 1208018 1 Battery compartment cover 1081458 1 Carrying case 1319067 1 Operation and Service Manual 1980145 Table 1b List of components Model 8370 5 Qty Item Part No 1 Model 8370 base 1081388 1 2 ft x 2 ft 610 mm x 610 mm hood fabric 1307060 1 2 ft x 4 ft 610 mm x 1220 mm hood fabric 1801065 1 1 ft x 4 ft 305 mm x 1220 mm hood fabric 1801066 1 1 ft x 5 ft 305 mm x 1525 mm hood fabric 1801067 1 3 ft x 3 ft 915 mm x 915 mm hood fabric 1801068 6 Frame support poles 1081390 6 2 ft 610 mm frame tubing 1081262 4 1 ft 305 mm frame tubing 1081260 6 Right angle tubing connectors 1081584 6 Straight tubing connectors 1302833 1 Battery holder 1081279 2 1x tube connectors 1081580 4 C size batteries 1208018 1 Battery compartment cover 1081458 1 Carrying case 1319067 1 Operation and Service Manual 1980145 Four of the 2
14. anging Dip Switch Settings in Chapter 2 Installing the Batteries The ACCUBALANCE requires four C size batteries to operate For your convenience four alkaline batteries are included with the ACCUBALANCE To install the batteries follow these three steps 1 Remove the battery cover located behind the electronic meter on the inner side of the ACCUBALANCE base To remove the battery cover pull up on the latches located on the top and bottom of the cover 2 Place batteries in the battery holder located inside the battery compartment Follow the illustration on the battery holder for correct battery orientation 3 Replace the battery cover Notice that the battery cover is designed to fit only one way with the tab pointing toward the fabric Engage the latches by pressing down on them WARNING Never leave batteries in the ACCUBALANCE for more than two weeks Leaking batteries can cause electronic failure due to corrosion Notice Remove batteries from the battery compartment during shipping travel and transport Jostling may jar the batteries loose and cause damage to the ACCUBALANCE 14 Chapter 1 Start Up Press the ON OFF button on the meter to turn on the power The display will initially indicate the percent of battery power remaining During start up the ACCUBALANCE performs a self test of its electronic functions If an error is found an error message will appear on the display Refer to Chapter 4 Troubleshooting
15. ch or the button on the right handle When making a flow measurement keep objects out of the flow path at the base of the ACCUBALANCE one foot clearance minimum However it is acceptable to have a hand supporting the flow hood at the bottom of the base Turning the ACCUBALANCE Off To turn off the ACCUBALANCE simply press the ON OFF switch Automatic Shut off The ACCUBALANCE will automatically shut itself off if no switches or buttons have been pressed for 15 minutes This feature minimizes accidental loss of battery power Set Up 17 18 Chapter 1 Chapter 2 Operations in More Detail This chapter explains how to change fabrics and assemble different hood sizes and presents more detail on the various features of the ACCUBALANCE Changing Hoods The ACCUBALANCE is shipped with a 2 ft x 2 ft hood attached to the base Four other hood sizes are available from TSI and can be purchased separately or as part of standard packages Available hood sizes are identified by the dimensions of the frame structure at the top of the hood and include 2 ft x 4 ft 1 ft x 4 ft 1 ft x 5 ft and 3 ft x 3 ft To change hood sizes first remove the hood currently attached to the base To remove the attached hood first unlatch the cinch belt where the fabric is attached to the base Then remove the fabric from its frame structure by peeling back the Velcro from the aluminum frame tubing Notice that the fabric stretches around the outsi
16. de then up and over the frame structure The Velcro on the fabric reaches down to mate with the Velcro on the frame structure Notice also that all Velcro surfaces on the frame tubing face inward Finally fold up the fabric you just removed so that it can fit into one of the accessory pockets inside the ACCUBALANCE carrying case It is a good idea to fold the fabric so that the tag identifying its size remains visible for future reference 19 2 ft x 4 ft Hood To assemble and attach the 2 ft x 4 ft hood carefully follow these 10 steps 1 Build the 2 ft x 4 ft frame structure as shown in Figure 7 using six 2 ft aluminum frame tubing pieces four right angle tubing connectors and two straight tubing connectors Remember to construct the frame so that all Velcro surfaces face in toward the center of the structure tubing pieces are facing downward Notice Make sure that all support pole cups in the aluminum frame Figure 7 Assembled 2 ft x 4 ft frame 2 Unfold the 2 ft x 4 ft hood fabric 3 Insert the frame into the fabric and fasten the fabric to the frame using the Velcro surfaces The fabric stretches around the outside then up and over the frame structure The Velcro on the fabric reaches down to mate with the Velcro on the inner surface of the frame structure When completed the soft rubber gasket material should lie in a straight line along the top surface of all four sides of the frame 20 Chapter 2 Notice Be sur
17. e base Air flowing through the hood is measured by a hot film sensor located in the central hub of the flow sensing manifold The twenty four pairs of flow sensing ports in the manifold are strategically located so that the ACCUBALANCE provides the highest degree of measurement accuracy even in non uniform flow conditions The ACCUBALANCE is temperature compensated to display a standard flow rate SCFM Std 1 s and Std m hr Standard flow rate is defined as the volumetric flow rate at standard conditions of 70 F 21 1 C and 14 7 pounds per square inch 760 mmHg barometric pressure Standard flow rate is the measurement used most often in ventilation applications Introduction Chapter 1 Set Up This chapter guides you through unpacking setting up and getting started using your ACCUBALANCE See Chapter 2 for a detailed description of all operating features Unpacking Carefully unpack the instrument and accessories from the carrying case Check the individual parts against the list of components in Table 1 If any are missing or damaged notify TSI immediately Table 1 List of components Qty Item Part No 1 Model 8370 base 1081388 1 2 ft x 2 ft 610 mm x 610 mm hood fabric 1307060 6 Frame support poles 1081390 4 2 ft 610 mm frame tubing 1081262 6 Right angle tubing connectors 1081584 1 Battery holder 1081279 4 C size batteries 1208018 1 Battery compartment cover 1081458 1 Carrying case 1319067 1 Operation and
18. e to press the Velcro surfaces firmly together When completed the hood fabric will be stretched fairly taut and will require good bonding of the fabric to the frame 4 Stretch the cinch belt at the bottom of the fabric over the lip around the top of the molded plastic base of the ACCUBALANCE Align the seams of the fabric panels with the pairs of screw heads that hold the four pole mounts to the ACCUBALANCE base Align so that the cinch belt latch is on the side of the base opposite the electronics meter 5 Pull the strap at the latch very tight to attach the fabric to the base Make sure that the strap stays tucked under the protruding lip all around the top of the base Pay particular attention to where the strap passes the handles 6 Nowitis time to install the support poles You will find four white marks on the inside top edge of the fabric These marks identify the location of cups on the underside of the frame tubing that will accept the ends of the support poles At this time it is helpful to be near a table or some other thigh high surface to help hold up the fabric while you install the first support pole refer to Figure 5 on page 12 7 With the base of the ACCUBALANCE on the floor lift the fabric frame up so that a white mark is directly in front of you Support the opposite side of the frame structure on a nearby table or other level surface as shown in Figure 5 Take one support pole and insert one end into its pole
19. fore using the instrument Formatting and Typography Note that step by step instructions are numbered in boldface type 1 2 3 etc set flush left against the margin References to the front panel keys on the ACCUBALANCE along with the instrument s displayed readout are represented in this manual by the typeface called Helvetica Narrow In addition to the different typeface displayed messages appear in quotes When reference is made to other sections of the manual the section title is italicized Example The HOLD message will appear along with a flow value after you have activated the HOLD button from Display in Chapter 1 HELP If you need technical assistance with this instrument have questions about the manual or your flow hood needs repair or recalibration please call TSI s Insustrial Test Instruments Group at 651 490 2711 or 800 777 8356 t About this manual Introduction The TSI Model 8370 ACCUBALANCE is an instrument designed to measure the air flow from diffusers and grilles or the air flow entering exhaust outlets The ACCUBALANCE is lightweight and easy to use The instrument can display the measured air flow in three different units standard cubic feet per minute SCFM standard liters per second Std 1 s and standard cubic meters per hour Std m hr The ACCUBALANCE consists of a fabric hood a molded plastic base which contains an electronic meter and a flow sensing manifold located within th
20. ft frame tubings and four of the right angle connectors are shipped assembled inside the top of the hood fabric 6 Chapter 1 Figure 1 The ACCUBALANCE and accessories Included with every manual is a registration card Look for yours at the front of this manual Please complete and mail it promptly it allows TSI to inform you of product updates Parts Identification Before proceeding with assembly and use of the ACCUBALANCE please familiarize yourself with the various parts of the instrument As you read the next sections refer to figures 2 4 Set Up 7 Figure 2 ACCUBALANCE components 1 Hood fabric 2 Base 3 PRINT button in left handle 4 START HOLD button in right handle 8 Chapter 1 Keypad an RETURN 4 SUPPLY Y DATA PORT Figure 3 Electronic meter membrane switch ON OFF Press to turn the ACCUBALANCE on and off PRINT Press to transmit the displayed flow rate measurement to the printer or other serial device Note that the button in the left handle performs the same function DATA PORT Printer or other serial device connection port Remove Data Port Plug before connecting serial device Set Up 9 START HOLD In the Averaging Mode press to start a new reading In the Continuous Reading Mode press and release to hold the value on display Press again to resume continuous readings Note that the button in the right handle performs the same function AVG CONT Press to switch between the Ave
21. g Preparing the Instrument for Use Hood Assembly The ACCUBALANCE is shipped from the factory partially assembled with the 2 ft x 2 ft nylon hood attached to the base If you wish to use another hood size see Changing Hoods in Chapter 2 Set Up 11 To complete the assembly of the 2 ft x 2 ft hood follow these six steps 1 Place the base of the ACCUBALANCE on the floor 2 Liftthe top of the fabric Insert one end of a support pole into its pole mount in the base of the ACCUBALANCE There is a cup in each corner of the frame to accept the other end of each support pole Helpful Hint This step is made simpler by temporarily resting the opposite corner of the fabric top on a table edge as shown in Figure 5 Figure 5 An easy way to begin assembly 12 Chapter 1 3 Grasp the support pole Bend the pole slightly to insert the top end of the pole into the support pole cup located in the corner of the fabric frame as shown in Figure 6 Figure 6 Installing a support pole 4 Insert the second support pole into the pole mount on the opposite side of the ACCUBALANCE base 5 Repeat step 3 for the second support pole 6 Repeat steps 4 and 5 for the remaining two support poles Set Up 13 Display Units The ACCUBALANCE is shipped with cubic feet per minute CFM as the default flow unit unless the metric version was ordered If you wish to change the units to 1 s liters per second or m hr cubic meters per hour see Ch
22. ground pin 7 pin 7 ground tied together pin 8 pin 20 data term ready Figure 17 25 pin RS 232 serial interface connections for personal computer The pins labeled tied together are connected together inside the ACCUBALANCE This puts the data set ready and clear to send lines at the proper logic level for your computer to receive data If you wish to connect the ACCUBALANCE to a computer which uses a 9 pin connector for serial communications an adapter may be used This is a standard 25 pin to 9 pin adapter with male pins on the 25 pin side and female pins on the 9 pin side Such an adapter is supplied with the Model 8927 Computer Interface Cable or is available from a number of computer supply houses Its connections are as follows 9 Pin Female Side 25 Pin Male Side Signal Name pin1 pin 8 carrier detect pin 2 pin 3 receive data pin 3 pin 2 transmit data pin 4 pin 20 data term ready pin 5 pin 7 ground pin 6 pin 6 data set ready pin7 pin 4 request to send pin 8 pin 5 clear to send pin9 pin 22 ring indicator Figure 18 25 pin to 9 pin RS 232 serial interface connections 46 Appendix C Appendix D Return Mode Low Flow Corrections The ACCUBALANCE is calibrated in a vertical position Thus in the Return Mode air is flowing up through the ACCUBALANCE base and then through the fabric hood When using the ACCUBALANCE in a horizontal orientation at flows below 100 CFM 50 1 s such as at a side wall return vent the ACCUB
23. ional Printer 19 19 26 26 27 27 28 28 29 32 32 33 ON ND OP WN PR RS 232 Serial Output Maintenance Fabric Hood Meter Manifold Calibration Troubleshooting Appendices Standard Flow vs Actual Flow Back Pressure ACCUBALANCE Serial Interface Connections Return Mode Low Flow Corrections Specifications Tables List of Components List of Components Model 8370 3 List of Components Model 8370 5 DIP Switch Settings Printout Examples Hood Fabric Part Numbers Troubleshooting the ACCUBALANCE Illustrations The ACCUBALANCE and Accessories ACCUBALANCE Components Electronic Meter Membrane Switch Electronic Meter Display An Easy Way to Begin Assembly Installing a Support Pole Assembled 2 ft x 4 ft Frame 33 35 35 36 36 37 39 41 43 45 47 49 32 33 35 39 10 12 13 20 10 11 12 13 14 15 16 17 18 Installing a Support Pole Assembled 1 ft x 4 ft Frame Assembled 1 ft x 5 ft Frame Assembled 3 ft x 3 ft Frame ACCUBALANCE Lying Face Down Location of DIP Switches Flow Sensing Tube Out of Place Pressure Drop Through the ACCUBALANCE 9 Pin RS 232 Serial Interface Connections 25 Pin RS 232 Serial Interface Connections 25 Pin to 9 Pin RS 232 Serial Interface Connections 22 23 24 25 30 31 37 44 45 46 46 iii iv About this manual This manual explains how to set up operate and maintain the Model 8370 ACCUBALANCE Flow Measuring Hood Read it thoroughly be
24. low Object is blocking flow through ACCUBALANCE Corrective Action Press ON OFF button Replace the batteries Clean the battery contacts Plug in battery holder Replace the batteries Clean the battery contacts Flow may not be measurable using the ACCUBALANCE Remove obstruction 39 Table 5 continued Symptom Flashing flow value gt 0 Flow is over range Flow reading fluctuates badly ERR2 appears ERR1 appears ERR3 appears 40 Possible Causes Sensor grid tubes are plugged ACCUBALANCE is not sealing around diffuser Trying to read too high a flow The flow is fluctuating The flow sensor is giving an erroneous reading Temperature compensation sensor is damaged Unit is or was recently in ambient temperature outside of operating temperature The ACCUBALANCE has detected a calibration fault Corrective Action Clean the tubes Reposition the ACCUBALANCE to form a seal Flow may not be measurable using the ACCUBALANCE Use a longer time constant Return to the factory for service Return to the factory for service Allow unit to stabilize in the operating temperature range of 32 140 F 0 60 C Return to the factory for service Chapter 4 Appendix A Standard Flow vs Actual Flow Standard flow is defined as the volumetric flow rate of air at Standard temperature and barometric pressure conditions of 70 F 21 1 C
25. ly and return air separately for increased accuracy The ACCUBALANCE will assume that air is flowing in the same direction as the arrow on the right hand side of the display Be sure this arrow points in the direction of flow through the ACCUBALANCE otherwise measurements will be inaccurate To change the direction of the arrow press the RETURN SUPPLY switch Taking a Flow Measurement You are now ready to start measuring flow rates First turn on the ACCUBALANCE and select the appropriate flow direction For measuring supply air flow the arrow must point down away from the hood fabric for return air flow measurements the arrow must point up toward the hood fabric Next choose the Continuous Reading Mode and be sure that the HOLD message is not on the display If the HOLD message is on the display press either the START HOLD switch on the keypad or the button on the right handle to resume readings Finally press the top of the ACCUBALANCE against the perimeter edge of the diffuser or grille so as to forma seal The electronic meter will display standard flow readings If the readings are fluctuating choose the averaging mode by pressing the AVG CONT switch on the keypad In the Averaging Mode it is important to keep the ACCUBALANCE in place over the diffuser or grille during the countdown and until the average reading appears on the 16 Chapter 1 display A new average reading can be initiated by pressing the START HOLD swit
26. mportant that you select the flow direction using the RETURN SUPPLY switch on the keypad before you make a measurement The arrow in the upper right hand area of the display will change direction each time you press the RETURN SUPPLY switch 26 Chapter 2 on the keypad Make sure the arrow is pointing in the direction of the flow before you make a measurement Continuous Reading Mode In this mode the display is continuously updated either once every second or every other second The ACCUBALANCE is shipped with a one second display update rate The update rate can be changed to once every two seconds by changing DIP switch 7 in the battery compartment see Changing DIP Switch Settings later in this chapter Changing the update rate to two seconds can help reduce fluctuations in the readings using the averaging mode will also help stabilize the readings The flow rate can be held on the display by pressing the START HOLD switch on the keypad or the button in the right handle This is a valuable feature if you do not have the optional printer The hold function will allow you to set the instrument down to manually record a measurement Of course the printer would make the job even easier With the printer all you would have to do is press the PRINT button instead of setting the instrument down and writing the value by hand To resume continuous readings when a value is being held on the display simply press the START HOLD switch or the but
27. ons The serial output from the ACCUBALANCE is transmitted in ASCII format Table 3 lists examples of the output from the ACCUBALANCE Table 3 Print out Examples Continuous Reading Mode Flow 435 CFM Flow 1580 m hr Flow 1321 s Operations in More Detail 33 Averaging Mode 3 sec Average 435 CFM 3 sec Average 1580 m9 hr 6 sec Average 132 1 s 34 Chapter 2 Chapter 3 Maintenance The ACCUBALANCE is designed for long term field use If the ACCUBALANCE is used with reasonable care it should be able to make precise measurements over a long time period Some of the components can be cleaned periodically When cleaning the components please follow the instructions given below Fabric Hood The hoods can be washed with mild detergent and cold water When washing the hood keep the hood away from objects with sharp corners or sharp edges Careless cleaning may cause damage If the fabric gets ripped it should be replaced or repaired Duct tape can be placed over the rip on both sides of the fabric for temporary repair To replace a damaged fabric or to order a different fabric size contact your local TSI distributor To determine who your local TSI distributor is you may call TSI toll free at 1 800 876 9874 If you wish to order a new hood fabric use the following part numbers shown in Table 4 Table 4 Hood Fabric Part Numbers Fabric Hood Size Part Number 2 ft x 2 ft 610 mm x 610 mm 800590 2 ft x 4
28. pressure In general back pressures are caused by restrictions in the flow path as well as frictional pressure losses In order to improve accuracy and sensitivity all flow measuring hoods incorporate a contracted flow section The contracted section restricts the flow through the hood which induces a back pressure A hood having a more abrupt contraction than the ACCUBALANCE may induce greater back pressure due to the turbulence caused by the abrupt contraction In addition any apparatus within the hood such as supporting poles and the flow manifold also induces some frictional pressure drop Back pressure may cause slight errors in the flow measurements Figure 15 shows the pressure drop through the ACCUBALANCE over its entire flow range As shown in the figure the back pressure is only 0 05 in H20 at a flow rate as high as 1000 CFM 43 Liters Sec 500 750 0 20 i tou 0 15 70 3 Pressure Drop Inches 0 10 70 2 H 0 mmHg 0 05 70 1 0 500 1000 bo 2000 Flow CFM Figure 15 Pressure Drop through the ACCUBALANCE If you wish to make back pressure corrections you must first determine the back pressure correction factor Cp The back pressure correction factor Cp can be determined as follows Vo Ge 8 1 V where V and V are the average air velocities in the duct ahead of the diffuser with and without the capture hood in place respectively With the known correction factor the back pressu
29. raging and the Continuous Reading Modes RETURN SUPPLY Press to switch between return air and supply air measurements Display a ACCUBALANCE LA mm Oo rerunNa Figure 4 Electronic meter display Figure 4 shows the electronic meter display All segments will be shown momentarily each time you turn on the ACCUBALANCE 10 Chapter 1 1 Flow units CFM cubic feet per minute l s liters per second and m3 hr cubic meters per hour The ACCUBALANCE indicates flow already corrected to standard conditions see Appendix A 2 Flow value See specifications for range and resolution 3 Flow direction arrow Indicates if supply or return air flow calibration is being utilized by the ACCUBALANCE Notice Be sure this arrow points in the direction of flow through the ACCUBALANCE otherwise the measurements made will be inaccurate To change the direction of the arrow press the RETURN SUPPLY switch 4 Averaging mode The AVERAGE message will appear on the display when you have selected the three second or six second averaging mode See Averaging Mode section later in this chapter 5 Hold indicator The HOLD message will appear along witha flow value after you have activated the HOLD button 6 LOW BATTERY Displayed when batteries are getting near the end of their useful life 7 BATTERY will appear along with a value on the display during power up to indicate the percent of battery life remainin
30. re corrected flow can be determined using Equation 8 2 Back pressure corrected flow Displayed flow x Cp 8 2 t 44 Appendix B Appendix C ACCUBALANCE Serial Interface Connections A 9 pin cable Model 8926 is available for use with the ACCUBALANCE and the TSI Model 8925 Portable Printer This cable allows a direct connection between the ACCUBALANCE and the printer Its connections are as follows Signal Name ACCUBALANCE Printer Signal Name tied together pin 1 pin1 tied together pin 2 pin7 pin 3 pin2 tied together pin 4 pin6 transmit data pin 5 pin3 receive data pin 6 pin9 signal ground pin 7 pin 5 signal ground tied together pin 8 pin 8 busy no connection pin 4 Figure 16 9 pin RS 232 serial interface connections for Model 8925 Printer All lines shown are connected but only the data line going to the printer and the ground are actually used in this configuration The pins labeled tied together are connected together inside the ACCUBALANCE A 25 pin cable Model 8927 is available for connecting the ACCUBALANCE to a personal computer This cable allows a direct connection between the ACCUBALANCE and the computer Its connections are as follows 45 Signal Name ACCUBALANCE Computer Signal Name tied together pin 1 pin 8 carrier detect tied together pin 2 pin 5 clear to send pin 3 pin 2 transmit data tied together pin 4 pin 6 data set ready transmit data pin 5 pin3 receive data pin 6 pin 22 ring indicator
31. rmal use for a period of 90 days from the date of shipment to the customer 3 Seller does not provide any warranty on finished goods manufactured by others Only the original manufacturer s warranty applies 4 Unless specifically authorized in a separate writing by seller seller makes no warranty with respect to and shall have no liability in connection with any goods which are incorporated into other products or equipment by the Buyer All goods returned under warranty shall be at the Buyer s risk of loss Seller s factory prepaid and will be returned at the Seller s risk of loss Buyer s factory prepaid THE FOREGOING IS IN LIEU OF ALL OTHER WARRANTIES AND IS SUBJECT TO THE CONDITIONS AND LIMITATIONS STATED HEREIN NO OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR PARTICULAR PURPOSE OR MERCHANTABILITY IS MADE THE EXCLUSIVE REMEDY OF THE USER OR PURCHASER AND THE LIMIT OF THE LIABILITY OF SELLER FOR ANY AND ALL LOSSES INJURIES OR DAMAGES IN CONNECTION WITH THIS PRODUCT INCLUDING CLAIMS BASED ON CONTRACT NEGLIGENCE STRICT LIABILITY OTHER TORT OR OTHERWISE SHALL BE THE RETURN OF THE PRODUCT TO THE FACTORY OR DESIGNATED LOCATION AND THE REFUND OF THE PURCHASE PRICE OR AT THE OPTION OF SELLER THE REPAIR OR REPLACEMENT OF THE PRODUCT IN NO EVENT SHALL SELLER BE LIABLE FOR ANY SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES SELLER SHALL NOT BE RESPONSIBLE FOR INSTALLATION DISMANTLING REASSEMBLY OR REINSTALLATION COSTS OR CHARGES
32. t before the ACCUBALANCE turns itself off Automatic Shut off The ACCUBALANCE has an automatic shut off feature to help save battery life If no switches or buttons are pushed for fifteen minutes the ACCUBALANCE will shut itself off 32 Chapter 2 Connecting the Optional Printer The ACCUBALANCE can be used with an optional portable printer The printer provides hard copy of selected flow rates and eliminates the awkward task of manually recording flow rates while operating a flow measuring hood To connect a TSI Model 8925 Portable Printer to the ACCUBALANCE locate the interface cable that was shipped with the printer The cable has a modular RJ 45 telephone type connector on one end and a 9 pin D connector on the other end Simply connect the 9 pin D connector to the printer and the RJ 45 connector to the ACCUBALANCE DATA PORT If you find that the printer prints only question marks turn the printer off and then on again For details about how to operate the Model 8925 Portable Printer refer to the manual that was shipped with it RS 232 Serial Output The DATA PORT on the ACCUBALANCE is used to interface to a printer digital data logger or other serial device The connector required for the RS 232 port on the ACCUBALANCE is an eight pin modular RJ 45 type connector For communications specifications and details about the cable wiring configuration of the RS 232 port refer to Appendix C ACCUBALANCE Serial Interface Connecti
33. ton in the right handle Averaging Mode This mode can be identified by the AVERAGE message appearing on the display You can toggle between continuous reading mode and averaging mode by repeatedly pressing the AVG CONT switch on the keypad Operations in More Detail 27 In the averaging mode the ACCUBALANCE takes flow measurements for three or six seconds and then displays and holds the time averaged flow The averaging time can be changed between three and six seconds by changing DIP switch 6 inside the battery compartment see Changing DIP Switch Settings later in this chapter The display will count down while the ACCUBALANCE is taking flow measurements Notice You must keep the ACCUBALANCE in place during the entire countdown and until the time averaged measurement appears on the display Selecting Flow Units The ACCUBALANCE is capable of displaying measured flow rates in three different measurement units CFM Cubic Feet per Minute l s Liters per Second and m hr Meters cubed per Hour DIP switches 3 and 4 control the display units Refer to Changing DIP Switch Settings later in this chapter to change the flow units Selecting the Time Constant The ACCUBALANCE allows you to choose between two measurement speeds in both the continuous reading mode and in the averaging mode In the continuous reading mode you may select either a one second or a two second display update rate The ACCUBALANCE is shipped from the
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