750 Series II CONDUCTIVITY/TDS & RESISTIVITY MONITOR/CONTROLLER Operation Manual 09 August 11 INSTALLATION • OPERATION • MAINTENANCE Conductivity/TDS Models: 756II, 757II, 758II & 759II Resistivity Models: 751II, 752II, 753II & 754II ACCURACY • RELIABILITY • SIMPLICITY Water Quality Instrumentation Accuracy • Reliability • Simplicity
i
750 Series II MONITOR/CONTROLLER QUICK REFERENCE GUIDE If you read nothing else in this manual please read this Quick Reference Guide. REASSEMBLY 1. Carefully reinstall the front panel, bottom first. Ensure no wires have been pinched between enclosure and front panel. 2. Reinstall the four (4) screws and tighten. 3. To operate, turn power ON. PLEASE READ and COMPREHEND ALL WARNINGS, CAUTIONS and ADVISEMENTS CONTAINED WITHIN THIS MANUAL.
connected to an appropriate Sensor, and that the Sensor is immersed in water within the range that the Monitor/controller will be required to read; and the front panel is removed. 1. Make a note of the reading on the display. 2. While pressing the Calibration/Full Scale Test Switch (FSSW), verify that the front panel display is indicating a full scale reading. If not, see Calibration, section V.C. 3. Press and hold the “SET POINT” switch on the front panel.
MICROSIEMENS / CM 750II HIGH SET POINT LOW 750 Series II Model 758 II -121-SC (A Digital Conductivity Monitor/controller, with a Range of 0-2000 µS, and a Second Alarm/control, Displaying Full Scale) 1
TABLE OF CONTENTS SECTION PAGE 750 Series II ILLUSTRATION (758II-121-SC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 A. SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TABLE OF CONTENTS Continued SECTION PAGE 2. Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 a. Set Point Conversion (SPC) / Reversing Set Point . . . . . . . . . . . . . . . . . . . . . . . 20 b. Set Point Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 c.
TABLE OF CONTENTS SECTION PAGE 5. Optional Front Panel Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 B. OEM FRONT PANEL INDICATORS & CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1. Red “Set Point” LED Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 2.
I. INTRODUCTION Thank you for selecting one of the Myron L Company’s 750 Series II Monitor/controllers. The 750 Series II is based on input from ‘you’ - our customers, time proven designs, and many years of instrumentation experience. Since 1957, the Myron L Company has been providing customers with quality products at an affordable price by designing and producing products that are Accurate, Reliable, Simple to use. Quality you have come to rely and depend on.
NOTE: 3 1/2 digit LCD may be replaced with either a 3 1/2 or a 4 1/2 digit backlit LCD - available as options. ACCURACY Analog Models: + 2% of Full Scale Digital Models: + 1 % of Full Scale SENSITIVITY 0.05% of span STABILITY 0.05% of span REPEATABILITY 0.1% of span CALIBRATION CHECK Built in full scale value RECORDER OUTPUT 0-10 VDC @ 5mA max.
E. SENSORS 1. CONDUCTIVITY/ TDS 750 Series II Conductivity/TDS Monitor/controllers use the CS51LC, CS51 or CS52 Series sensor depending on range. The 1.0 cell constant CS51 model is recommended for ranges of 0-10 through 20,000 µS/ppm. Its compact size allows mounting in a standard 3/4” tee. The sturdy polypropylene bushing is modular for easy, inexpensive replacement. Other models available by special order. CS52 sensors have a 10.
G. 750 SERIES II RANGE SELECTION GUIDE CONDUCTIVITY/TDS & RESISTIVITY Add Range NUMBER below to instrument model number, i.e. 758II-”112” = 0-50 ppm Digital Monitor/controller.
II. INSTALLATION A. GENERAL This section provides the recommended procedures for properly installing the 750 Series II Conductivity/Resistivity Monitor/ controller, and sensors. For OEM models see section C. ! CAUTION - READ FOLLOWING CAREFULLY WARNING: THE Myron L COMPANY RECOMMENDS THAT ALL MOUNTING AND ELECTRICAL INSTALLATIONS BE PERFORMED BY QUALIFIED PERSONNEL ONLY. FAILURE TO DO SO COULD CAUSE DAMAGE TO INSTRUMENT, AND COULD BE HARMFUL OR FATAL TO PERSONNEL. B.
4. 5. 6. Slide the enclosure through the panel cutout until its flange contacts the panel. Insert mounting screws through the flange mounting holes and tightly secure. Reconnect all panel cable(s)/wire(s) and resecure the front panel using 6-32 x 3/8” screws provided. Caution: Do not use 6-32 x 1/2” used on “picture frame” front panel models. C. OEM MECHANICAL INSTALLATION .125 X4 (3.125) 1.880 (47.75) 2.218 Dia. 56.34 .940 (23.
D. SENSOR INSERTION/IMMERSION MOUNTING The Sensor’s mounting orientation must provide a continuous and adequate circulation flow to prevent the trapping of air bubbles within the Sensor’s electrode area (CS51 shown in figure II.D.1). Failure to do so will result in conditions that will prevent the Sensor from functioning properly. 1. INSERTION MODE (in-line installation) Use approved sealant, i.e. Teflon tape as required. 1. 2.
2. 115/230 VAC CONVERSION Before turning power on to the Monitor/controller ensure the proper input voltage has been selected. Failure to do so will blow the fuse. It could, under some conditions, cause injury and damage the instrument voiding the warranty. Locate switch located next to the fuse holder. Using a screwdriver, turn switch to required voltage. 3. CONNECTING THE SENSOR CABLE For OEM models skip #1. 1.
d. 5. 6. 7. Install 5.49kΩ resistor at RED (RD) and the NEUTRAL (NU) connector locations, as shown in figure II.E.5. Carefully reinstall the front panel, bottom first. Ensure no wires have been pinched between enclosure and front panel. Reinstall the four (4) screws and tighten. To operate, turn power ON. NOTE: Recalibration will require both the solution and sensor be at 25°C for maximum accuracy.
c. Connect to your own alarm or ? Use the following as guidelines. Connector is a standard 2 wire Methode* style connector. Connector with 8” wires, part #RAH, is available from the Myron L Company. Ensure your requirements do not exceed the 24VDC Unregulated 30mA maximum. Ensure the polarity is correct (RED is positive), see figure V.A.1. Attach wires to RA. Attach connector to controller connector (RA) per figure V.A.1.
F. 0-10 VDC RECORDER OUTPUT The 0-10 VDC output is designed to give the user the capability of sending a signal to a remote meter, recorder, PLC or SCADA system. 1. 2. 3. 1. CONNECTION Place the user supplied interface cable and watertight cable restraint into the enclosure’s appropriate access hole. Skip for OEM. Connect the Recorder’s plus (+) and minus (-) terminal wires to the Recorder output connectors. (See figure II.E.1.) Refer to Section V.C.1.
G. RE-RANGE YOUR MONITOR/CONTROLLER (Range Module Installation) 3. 4. 1. DESCRIPTION The 750 Series II Monitor/controllers have been designed for easy field re-rangeability. The Range Module consists of a 16 pin Header that plugs into a 16 pin socket. For available ranges, see Range Selection Guide I.G. When making large range changes, i.e. 5000 ppm to 50 ppt, a different sensor may also be required as noted in the Range Selection Guide.
3. CHANGING ANALOG METER SCALE (DIAL) After changing ranges on an analog model 750II it may be necessary to change the meter scale (dial). The following steps will guide you through the change. Please read caution carefully. ! CAUTION - READ FOLLOWING CAREFULLY 6. To remove the scale, lightly press on bottom of scale, the top will lift up. Be extremely careful not to bend the pointer (needle) or to move the Zero Adjust (ZA). See figure II.G.7.
Grasp Scale Here and Slide Out TOP 0 SCALE (dial) 0 Align Pointer with FIRST Line Pointer (needle) 1/8" (3.18mm) Hex Screws (2) Press Lightly Here Zero Adjust (ZA) CLEAR PLASTIC COVER METER CASE Figure II.G.7 4. LABEL CHANGE Since you have re-ranged your Monitor/controller it may be necessary to relabel it. If you made any one of the following changes it will be necessary to “add or change” the designator label on the Front Panel.
III. OPTIONS & ACCESSORIES ! A. SC/SCO MODULE (SECOND ALARM/CONTROL OPTION) (Digital & OEM Models ONLY) -SC SCO Second Alarm Control Module ordered with Monitor/controller. Second Alarm Control Module Kit ordered separately. 1. DESCRIPTION: An essential component for applications requiring a DUAL setpoint. The Second Alarm/control module allows the user additional flexibility by being able to sound TWO Alarms, and Control TWO functions with the second 10 amp relay.
Front Panel WARNING: There are two (2) O-rings installed on the switches, one (1) on the shank and the other is under the push button. Both of these O-rings must be reinstalled to maintain IP65/ NEMA 4X ratings. See figure III.A.3. 1-4 assumes this is a conversion from a single alarm/control. Skip to #5 if new installation or assembly. 1. 2. 3. 4. 5. 6. Carefully remove the RED LED from the front panel by pulling lightly on the wires.
The following instructions describe the steps for converting the Monitor/controller. Refer to figure III.A.4 for the location of the SPC(s) on your Monitor/controller. If unnecessary, skip to Set Point Adjustment. 1. 2. 3. 4. 5. 6. Ensure power is OFF. Locate the SPC jumpers for the alarm to be configured, see figure III.A.4. Make a note of the current orientation of the SPC jumpers. Remove both jumpers. This is easily done by hand. Take care not to crush the jumpers if using pliers.
c. Hysteresis (Dead Band) Adjustment* The hysteresis or dead band is approximately ±3% of the set point at full scale as it leaves the factory. Under normal (most) conditions it will not be necessary to adjust. However, if you desire to make an adjustment please keep the following in mind. The adjustment is very simple and is based on set point location. If the set point* is in the upper 75-100% of the scale, the hysteresis control pot should be turned fully to the right.
B. 4A/4AO MODULE (4-20mA OPTION) Available only on the digital models 758II, 759II, 753II and 754II, or all analog and digital OEM Monitor/controllers. -4A 4AO 4-20mA Self/Remote-powered Isolated output module ordered with Monitor/controller. 4-20mA Self/Remote-powered Isolated output module ordered separately (includes harness). 1.
FATAL TO PERSONNEL. ONLY QUALIFIED PERSONNEL SHOULD INSTALL ELECTRICAL EQUIPMENT. Physical If the front panel has all ready been removed from the enclosure skip to #3. 1. 2. 3. Using a standard slot screwdriver remove the four (4) screws on the front panel. Carefully wiggle the front panel to loosen and pull gently toward you. Do not pull more than about 8 inches/ 20CM or you could damage the wiring harness. Turn the front panel around so that the back side is facing you.
5. SENSOR LEADS JUMPER FULL SCALE TEST SWITCH 0-10VDC BK WT RD GN NU R- R+ 3S FS SW SP1 HYS1 756 757 758 759 PA RA MYRON L COMPANY FUSE* CHS TRANSFORMER 115/ 230 4-20 CONNECTOR CONNECT 4AO HARNESS HERE REMOVE TO INSTALL SECOND RELAY 751 752 753 754 12. 13. 14. SPC 4-20 -121 2000µS DIS 8. 9. 10. 11. PWR C GD NC NO CM GND UP INC DEC } CAL 6. 7. If not, adjust the CAL control marked “4mA” until the DVM indicates 4mA, see figure III.B.3.
4. CONVERTING A CURRENT TO A VOLTAGE Current measuring devices actually measure voltage, but have an internal resistor as shown in figures III.B.1 & III.B.2 and are scaled to display in current. If you have a voltage input instrument and you wish to utilize the current from the 4A (4-20mA) Module, the following will help you to make this conversion.
C. TEMPERATURE MODULE (Digital Models only) -TP Temperature Module ordered with Monitor/controller. TPO Temperature Module Kit ordered separately. Requires; CSXX-TP sensor, Special Order, i.e. CS51-TP or CS40-TP, see sensor data sheet. NOTE: OEM models require an additional display harness, part number TPMH. See OEM Installation. 1. DESCRIPTION The Temperature Module (TP) gives the Monitor/controller more flexibility for the user by being in the same package.
5. 6. 7. 8. Set front panel down or carefully allow to hang from the harness. Do not drop as the harness connector will pull out allowing the front panel to fall. While holding the display and the plastic display retainer plate, carefully remove the display harness connector. Do not drop the display. Remove and discard the plastic display retainer plate. Insert display connector pins into the Temperature Module female connector. See figure III.C.1. 9.
Figure III.C.6 TPC Module PRESS BUTTON FOR 199.9ºC/5.0VDC Press TPC Module into TPO connector as shown. 0-5VDC + OUTPUT ORANGE BLUE BROWN MYRON L COMPANY 0-5VDC + OUTPUT ORANGE BLUE BROWN a. TPC “Calibration” Module Procedure This procedure assumes the front panel is removed. 1. Ensure power is OFF. 2. Remove the sensor leads from the Temperature Module. 3. Remove the 0-5VDC leads from the Temperature Module. 4.
19. Continue or reinstall the front panel and tightly secure four (4) retaining screws, see REASSEMBLY below. *CAUTION: The sensor input and 0-5VDC output connectors require only a small screwdriver or a pen to push on the release levers. The release levers may be broken or damaged if not pushed straight toward the CB. DO NOT push the release levers sideways. 1000.0Ω RESISTOR - + JUMPER 0.0 DV Connect DVM leads as shown. 3. 4. 5. 6. into slurry. Allow to equilibrate.
3. 4. 5. 6. counterclockwise position. If not, turn SCO Set Point control fully CCW - it may be 30 turns - or until it clicks. For location see figure III.C.13. Turn power ON. Press BOTH the Temperature Select switch and the Set Point switch on the front panel. Adjust the TP/TPO Module Set Point Two (SP2) to temperature as desired. See figure III.C.1. Turn power OFF. FS SPC INC INC SET POINT CONVERSION (SPC) DEC DEC c.
5. OEM INSTALLATION a. Single Display Models An OEM installation requires an additional display harness, part number TPMH. This harness is installed between the Temperature Module and the panel display as shown in figure III.C.14. Both connectors must be installed with the wires down or toward the bottom of the circuit board.
6. OEM INSTALLATION b. Dual Display Models SPECIAL ORDER These models allow simultaneous display of both Cond/TDS, RES or pH/ORP and Temperature. They require two display harnesses. The Cond/TDS, RES or pH/ORP display harness is part number DH2DD without control feature, or part number DHDD with control feature. The Temperature display harness is part number TPMH.
1. DESCRIPTION The optional TH/THO Controller Kit adds more flexibility to the Temperature Module by adding the ability to Alarm and/or Control using the 24VDC solid state output to drive a PA - Piezo electric alarm, and/or a 10 amp relay to operate a heater or chiller as required. a. HIGH Primary Control If the front panel has all ready been removed from the enclosure skip to step 3. 1. Using a standard slot screwdriver remove the four (4) screws on the front panel. 2.
by pulling lightly on the wires. It may be necessary to use a small flat screwdriver to slightly spread the retaining ring. See figure III.D.1. b. Remove Set Point Switch from the front panel, figure III.D.1, by rotating the round bezel nut CCW on the front as shown in figure III.D.2. c. Remove SCH harness from SC Module by on pulling harness. d. Set SCH harness aside, it is no longer used. 4.
4. c. Remove harness from SCO Module by pulling on harness, see figure III.D.3. d. Set SCH harness aside, it is no longer used. Remove SPC jumpers (2) from SC/SCO Second Alarm/Control Module, see figure III.D.3 for SPC jumper location.
SP2 HYS2 DIS ZERO FS SPC DEC DEC DEC DEC TP/TPO - TEMPERATURE MODULE TEMP CONTROL HARNESS DISPLAY REMOVE SC/SCO SET POINT SWITCH and RED LED TEMPERATURE LABEL LOCATION 750 II TEMPERATURE HIGH SET POINT LOW TEMPERATURE DISPLAY CONNECTION Figure III.D.10 Turn SCO Set Point control fully counter clockwise — it may be 30 turns - until it clicks. See figure III.D.7 for location. 9. Locate and remove JUMPER from option to the TPO Module as shown in figure III.D.5. 10.
FOR TEMPERATURE MODULE Temperature Set Point Adjust 1. Ensure the SCO Module Set Point control is set to FULL CCW position. For location see figure III.D.7. 2. Press BOTH the Temperature Select switch and the Set Point switch on the front panel. 3. Adjust the TP/TPO Module Set Point Two (SP2) to temperature as desired. See figure III.D.9. SPC SET POINT CONVERSION (SPC) DEC DEC TEMP CONTROL HARNESS DETAIL OF SET POINT CONVERSION (SPC) ON TP/TPO MODULE AS CONFIGURED WHEN SHIPPED FROM THE MFR.
E. INSTALLATION OF BOTH TEMPERATURE MODULE & 4-20mA OUTPUT MODULE (Digital and OEM Models ONLY) -TP/TPO Temperature Module. -4A/4AO4-20mA Self/Remote-powered Isolated output module. 1. DESCRIPTION The following instructions describe how to install BOTH the 4A/4AO and the TP/TPO Modules to a Digital model Monitor/ controller. SCREWS 4A/4AO PLASTIC SPACERS (4) TP/TPO Specifications See individual Data Sheets and installation instructions. Requires Plastic Spacers P# SP4819. 2.
F. 3SO 3SE 3 SENSOR INPUT MODULE 3 Sensor Input Module with 3 foot / 1 meter cable ordered separately (customer installed and mounted). 3 Sensor Input Module with 3 foot / 1 meter cable AND separate Enclosure (as an accessory). Enclosure is the same size as the Monitor/controller - 4.8”W x 6”H x 3.9”D. (CB) at the sensor input connectors.
ON Figure III.F.4 COND RES X1 X10 X100 S1 S2 S3 ON Figure III.F.3 Figure III.F.2 COND RES X1 X10 X100 S1 S2 S3 ON COND RES X1 X10 X100 S1 S2 S3 COND RES X1 X10 X100 S1 S2 S3 ON Figure III.F.5 Factory Default Module to the main Monitor/controller CB at the sensor input location as shown on label. Attach the separate small cable harness from the 3 Sensor Input Module to the small 2 pin male connector located to the left of the sensor input connectors on the main CB.
figure III.F.4. To disable the Sensor alarm/control function completely. 1. Locate the 8 position select switch on the 3S Module. 2. Set all S prefixed select switches in the OFF position, see figure III.F.5. 3SE MODULE with ENCLOSURE If adding an alarm/control sensor. 1. Locate the 8 position select switch on the 3S Module. 2. Set appropriate select switch DOWN or ON, i.e. to add S3 sensor, set switch marked S3 ON, see figure III.F.8. If changing alarm/control from one sensor to another, i.e.
G. 3 RANGE SWITCH MODULE ELECTRICAL EQUIPMENT. 3RO 3RE 3 3 Range Switch Module with 3 foot / 1 meter cable ordered separately (customer installed and mounted). Range Switch Module with 3 foot / 1 meter cable AND separate Enclosure (as an accessory). Enclosure is the same size as the Monitor/controller - 4.8”W x 6” H x 3.9”D.
3RO Module as an accessory you may need to reconfigure the select switch for it to Range properly. 1. Locate the 8 position select switch on the 3R Module. 2. Set the COND select switch in the DOWN or OFF position, see figure III.G.6. 3. Set the RES select switch in the UP or ON position, see figure III.G.6. BK WT RD GN NU R- R+ } 3SR MODULE 3S 3S RANGE SWITCH COND RES X1 X10 X100 S1 S2 S3 SELECT SWITCH ON -121 2000µS UP MAIN CIRCUIT BOARD NOT INSTALLED ON MONITOR ONLY MODELS. Figure III.G.
H. 3 SENSOR / 3 RANGE MODULE 3SRO 3 Sensor / 3 Range Switch Module with 3 foot / 1 meter cable ordered separately (customer installed and mounted). 3SRE 3 Sensor / 3 Range Switch Module with 3 foot / 1 meter cable AND separate Enclosure (as an accessory). Enclosure is the same size as the Monitor/controller 4.8”W x 6”H x 3.9”D. 1.
SENSOR INPUT Sensor Connections For convenience, it is recommended you connect the Primary or controlling sensor to SENSOR 1 position as shown in figure III.H.1. } UP 3S SELECT SWITCH ON SENSOR 2 SENSOR 1 SENSOR 1 NOT INSTALLED ON MONITOR ONLY MODELS. BK WT RD GN NU SENSOR 2 MAIN CIRCUIT BOARD SENSOR 3 BK WT RD GN NU 3S RANGE SWITCH -121 2000µS SENSOR SWITCH BK WT RD GN NU R- R+ SENSOR OUTPUT BACK/CONNECTOR SIDE COND RES X1 X10 X100 S1 S2 S3 3SR MODULE TO SENSOR INPUT Figure III.H.
For Conductivity/TDS - X1, X10 and X100. For Resistivity - X1, 0.1, and 0.01. Figure III.H.6 ON Factory Default Figure III.H.7 Figure III.H.8 ON COND RES X1 X10 X100 S1 S2 S3 ON COND RES X1 X10 X100 S1 S2 S3 COND RES X1 X10 X100 S1 S2 S3 ON COND RES X1 X10 X100 S1 S2 S3 If adding an alarm/control range. 1. Locate the 8 position select switch on the 3SR Module. 2. Set appropriate select switch UP or ON, i.e. to add X100, set switch marked X100 UP or ON, see figure III.H.7. Figure III.H.
I. PIEZO ELECTRIC ALARM -PA PAO Piezo Electric Alarm ordered with Digital Monitor/controller. Piezo Electric Alarm ordered separately for Digital or remotely mounted Analog Monitor/controller or OEM models. 1. DESCRIPTION The PA/PAO is an electronic sound device capable of emitting a 80dB or more @ 30cm, high pitched squeal. See figure III.I.1. Specifications Oscillating Frequency — 3.0≠0.5KHz Operating Voltage (750II) — 24VDC Nom. (1.5-30VDC Max.
a. For a Conductivity/TDS Monitor/controller, as shipped from the Myron L Company, the alarm will sound off when the Full Scale Test Switch is pressed. b. For a Resistivity Monitor/controller, as shipped from the Myron L Company, the alarm will sound off when the power is applied and stop when the Full Scale Test Switch is pressed. c. If the Set Point Conversion (SPC) jumpers have been reversed, the opposite will be true in the above descriptions. 2. Turn power OFF.
J. REMOTE ALARM - RA™ RA Ordered as an accessory, includes 8” harness with connector, and two (2) wire nuts. 1. DESCRIPTION This remotely mounted AUDIBLE and VISUAL alarm connects to any Myron L Company Monitor/controller, or brand “X” controller with dry contacts. When activated by the controller the Remote Alarm will provide both an audible and a visual alert at a location other than at the controller.
10. 11. 12. 13. 14. alarm for approximately three minutes or until you improve the water quality (readjust controller set point). If three minutes muting is fine for your application, skip to #10. If three minutes is too long or too short, adjust control inside RA until desired mute time is achieved (adjustable from approximately 15 seconds to 10 minutes). See figure III.J.1. Replace the bottom of the RA, and secure to surface you have selected for its installation.
IV. OPERATING PROCEDURES A. FRONT PANEL INDICATORS & CONTROLS The front panel illustrations to the right, switch and indicator operational descriptions have been provided to assist the user in identifying and operating the 750 Series II Monitor/controllers. For OEM models see Section B. Refer to Section IV.C for Setup procedures and Section IV.D for Check-Out procedures. 1.
B. OEM FRONT PANEL INDICATORS & CONTROLS The simulated OEM front panel illustrations to the right, and switch and indicator operational descriptions have been provided to assist the OEM user in identifying and operating the 750 Series II Monitor/controllers. Refer to Section V.C. for Setup procedures, and Section V.D. for Check-Out procedures. 1.
! C. CAUTION - READ FOLLOWING CAREFULLY SETUP PROCEDURES These Setup procedures cover (1) converting the alarm circuit to trigger on a decreasing (conductivity) or increasing (Resistivity) reading, (2) checking out your new Monitor/controller, (3) setting the alarm circuit setpoint(s), and (4) adjusting the hysteresis. The following require that the front panel be removed. While doing so be careful not to strain the cable(s).
CAUTION: adjusting the hysteresis too tight may cause the alarm to fluctuate (on-off) due to flow, chemical mixing or bubbles causing the relay to chatter. This condition is to be avoided, it could damage your valves, pumps, etc. and will eventually damage the relay. * Applies to both set points if so installed. The following is assuming the front panel is already removed and the set points have been set, if not see above, 1. 2.
V. COMPONENT IDENTIFICATION, CALIBRATION AND PREVENTIVE CARE A. PRIMARY COMPONENT IDENTIFICATION As identified in Section III, the Monitors/controllers switch(es) and indicator components are mounted directly to the front panel. The Monitor/controllers main circuit board is contained within and mounted to the back of the enclosure. Some models with options have an additional circuit board mounted behind the front panel, i.e. Model 758II-4A (4-20 Module). Review figure V.A.
! CAUTION - READ FOLLOWING CAREFULLY B. METER MECHANICAL ZERO PROCEDURES ANALOG METERS ONLY 1. Ensure power is OFF. 2. Note the position of the meter needle. If it has come to rest pointing at the zero mark on the scale, turn the Monitor back ON and continue on to Section V.C. 3. Locate the small (approx. 1/4”), black plastic button directly below the center of the meter. Use a small screwdriver or a fingernail to gently pry it loose and remove it from the access hole. See figure II.G.9. 4.
3. 4. 5. 6. Slowly shake the sensor to remove air bubbles from inside the sensor bore hole. Allow 5-10 minutes for temperature to equilibrate. For the quickest and the best results, both the sensor and solution should be at the same temperature. Turn power ON. Read the display of the instrument. The display should match the value and units of measure located on the bottle of standard solution.
4. TRANSFER STANDARD METHOD For maximum accuracy of any Monitor/controller, the transfer standard method should be utilized. Instead of removing the entire Monitor/controller and sensor, and either returning it to the manufacture or sending it to a third party laboratory for recertification, the transfer standard allows quick recertification and return to service — less down time.
VI. OPTIONS & ACCESSORIES A.
C. STANDARD SOLUTIONS & BUFFERS 1. CONDUCTIVITY/TDS STANDARD SOLUTIONS Your Conductivity/TDS Monitor/controller has been factory certified to meet certain specifications based on the appropriate Myron L Company NIST traceable standard solutions. These same solutions are available to you. DESCRIPTION The Myron L Company manufactures three basic types of conductivity/TDS standard solutions — KCl, NaCl and 442™. See below.
VII. REPLACEMENT PARTS MODEL DESCRIPTION ELECTRONIC MODULE CONDUCTIVITY 756CB................................756II Circuit Board Analog Monitor only 757CB................................757II Circuit Board Analog Monitor/controller 758CB................................758II Circuit Board Digital Monitor/controller 759CB................................759II Circuit Board Digital Monitor only RESISTIVITY 751RB................................751II Circuit Board Analog Monitor only 752RB..................
VII. REPLACEMENT PARTS Continued ENCLOSURE 700II ECP..........................750II Rear Housing (Box) for Picture Frame Front Panel 700II ECR..........................750II Rear Housing (Box) for Roll-off Front Panel FRONT PANEL with UPPER and LOWER LABELS Only (Must select Resistivity or Conductivity type) Add “P” for Picture Frame Front Panel style or “R” for Roll-off Front Panel Style, i.e. 751FPR 751/756FP..........................Analog Front Panel 751/756FP-PTS..................
VIII. WARRANTY All Myron L Company Conductivity/TDS and Resistivity Monitor/controllers have a TWO Year Limited Warranty. If any Monitor/controller or sensor fails to function normally, return the faulty unit to the factory prepaid. If, in the opinion of the factory, failure was due to materials or workmanship, repair or replacement will be made without charge. A reasonable service charge will be made for diagnosis or repairs due to normal wear, abuse or tampering.
IX. GLOSSARY 442™ An Internationally recognized “natural water” standard developed by the Myron L Company in 1964. Algorithm A procedure for solving a mathematical problem. See Addendum, Temperature Compensation and TDS Derivation. Anions Negatively charged ions DVM Digital Volt Meter Hysteresis Dead Band — related to alarm setpoint. The amount of delay or overlap between change from high to low or low to high.
X.
XI. ADDENDUM A. CONDUCTIVITY, TDS AND TEMPERATURE RELATIONSHIPS 1. TEMPERATURE COMPENSATION (Tempco) of Aqueous Solutions Electrical conductivity indicates solution concentration and ionization of the dissolved material. Since temperature greatly affects ionization, conductivity measurements are temperature dependent and are normally corrected to read what they would be at 25°C. a.
XI.
XI.
XI.
Myron L COMPANY 2450 Impala Drive Carlsbad, CA 92010-7226 USA Tel: +1-760-438-2021 Fax: +1-760-931-9189 E-Mail: info@myronl.com techquestions@myronl.com www.myronl.
