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Catalog Number 16116

8450 Residual Free Chlorine Monitor

INSTRUMENT MANUAL

© Hach Company, 2003. All rights reserved. Printed in the U.S.A.

ap/dk 07/03 2ed

Summary of Contents for 8450

Page 1: ...Catalog Number 16116 8450 Residual Free Chlorine Monitor INSTRUMENT MANUAL Hach Company 2003 All rights reserved Printed in the U S A ap dk 07 03 2ed ...

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Page 3: ...14 2 6 Electrical Connections 16 2 6 1 ac Power 16 2 6 2 Relay Alarms and Output Connections 17 2 6 3 Connecting the Probe 17 2 7 4 20 mA Surge Protector 18 2 7 1 Connections and Setup 19 2 7 2 Test and Check Procedure 20 2 7 3 4 20 mA Device Connection 20 2 8 Data Communications 21 2 8 1 RS232 Communications 21 2 9 RS485 Communications 23 2 10 Probe Preparation 24 2 11 New Membrane Pre qualificat...

Page 4: ...alibration 37 3 15 1 Preparation 38 3 15 2 Optimizing Span Calibration 38 3 15 3 Span Calibration Procedure 39 3 16 Relative Probe Sensitivity 39 3 17 Alarm Setup 40 3 17 1 Set Point Adjustment 40 3 17 2 High Set Point Setup 40 3 17 3 Low Set Point Setup 40 3 17 4 Selecting Alarm Relay Options lfit 41 3 17 5 Check Alarm Relay Setup 41 3 17 6 Alarm Time Delays 42 3 18 VMA Output Setup 42 3 19 Syste...

Page 5: ...olation 54 4 3 Resolving Calibration Problems 54 4 3 1 Timer Expires During Zero Calibration 55 4 3 2 Timer Expires During Span Calibration 56 4 4 Reading Drifts After Span Calibration 57 4 5 Calibration Error Messages 57 4 6 Calibrating with a Simulated Input 57 4 6 1 Equipment Required 57 4 7 CHECK Messages Alphabetical Listing 59 4 8 Resetting Factory Defaults 60 Replacement Parts and Accessori...

Page 6: ... not observed This symbol if noted on the instrument references the instruction manual for operation and or safety information This symbol when noted on a product enclosure or barrier indicates that a risk of electrical shock and or electrocution exists and indicates that only individuals qualified to work with hazardous voltages should open the enclosure or remove the barrier This symbol when not...

Page 7: ...on and temperature F and C 2 4 20 mA or 20 4 mA isolated into 800 ohm max 2 0 1 or 0 5 V dc Alarm Relays 2 5A SPDT 110 V ac 1 5A SPDT 110 V ac Alarm Relay Controls Latching fail safe inhibit and test Security Features 3 digit entry w confirmation Probe type Temperature compensated RTD direct sensing membrane probe Probe Temperature Limits 0 to 50 C 32 to 122 F Max pressure at probe 50 PSI Probe Ma...

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Page 9: ...spond to both hypochlorous acid and the hypochlorite ion Probes respond best in liquid environments of up to a pH of 9 however probes should be calibrated in the pH at which measurements will be taken to obtain optimum accuracy The probe can be used in a constant head flow assembly that provides better flow control and enhances the operating environment for the probe 1 2 Overview of Chlorine Chara...

Page 10: ... Depending upon expected pH swings the Free Chlorine probe response is not significantly affected below a pH of about 8 If the pH is constant the probe can be calibrated and used at up to pH 9 however large pH swings centered at about pH 9 can cause errors If the pH is to be kept between 5 and 6 i e 100 HOCl residual a Sigma CO2 Sparging system is recommended Figure 1 HOCl OCl Equilibrium and Sigm...

Page 11: ...Mounting The programmable electronic monitor is enclosed in a NEMA 4X enclosure that can be mounted to a wall through a panel or onto a handrail or pole 2 2 1 Wall Mounting Two mounting brackets one on each side are attached to the monitor with four screws supplied With the bracket tabs and mounting holes extending beyond the monitor on each side the monitor can be attached to a wall or flat surfa...

Page 12: ...optional junction box near the probe location The junction box contains a receptacle for plugging in the probe see Figure 11 on page 18 The junction box should be no more than 200 feet from the monitor 2 3 2 Panel Mounting Sequence To attach the panel mount kit brackets refer to Figure 5 and Figure 6 and proceed as follows 1 Attach the Z brackets Cat No x using 1 4 20 x 0 25 L hex bolts at the bac...

Page 13: ...anel Mount Attaching Parts Side View 1 Enclosure Plate 4 Panel 2 10 32 x 0 75 stainless slotted hex washer head machine screw 5 1 4 20 x 0 25 stainless steel machine screw 3 1 4 20 x 0 75 stainless slotted hex wahser head machine screw 6 Z bracket RESIDUAL CHLORINE MONITOR 8 2 20 8 cm 10 7 27 1 cm 6 5 4 3 2 1 ...

Page 14: ...the pipe mounting kit does not include the pipe 2 5 2 Flow Cell Mounting Use a flow cell for free chlorine applications in situations where a uniform flow across the membrane cannot be assured by other means The flow cell assembly contains a clear flow block into which the probe is inserted and a constant head overflow that controls the flow through the cell The flow cell will operate with a minim...

Page 15: ...igure 8 Submerged Probe Using Pipe Mount Kit 1 Probe Cable to Monitor 5 1 2 54 cm FNPT 2 1 5 3 8 cm diam Handrail 6 Probe Adapter Cone 3 1 2 54 cm Schedule 80 PVC pipe Customer supplied length as required 7 Probe 4 Probe 8 Pipe Bracket 6 5 4 3 2 1 8 7 ...

Page 16: ...d alarm relays if they are being used Figure 10 shows the terminals to which connections are made for the various functions If the unit being installed is a 1 Mounting Plate 5 Water Line 2 Flow Cell 6 Pressure Regulator 10 15 psi Output 3 0 5 Outlet 7 0 25 Inlet Inlet Flow 8 to 25 gph 4 Hand Valve 8 0 20 3 cm 7 5 19 1 cm 6 0 15 2 cm 5 5 14 0 cm Mounting Plate Flow Cell 0 5 Outlet Hand Valve Pressu...

Page 17: ...e proceeding In order to access the terminal strip to make relay and output connections remove the four screws from the front panel and remove the front panel Next remove the two screws on the right side of the display board the display board is hinged and swing the display board out of the way Make all necessary connections in accordance with the Figure 10 and reassemble the enclosure Connection ...

Page 18: ... straight slot screw driver Direct Connection Connection Using Screw Teminal Junction Box Probe Connector P1 Junction Box Cable Removable Face Plate Probe Connector Leads End Connector Junction Box Table 1 Probe Conductor Identification Probe Cable Color Junction Box Bendix Connector P2 Junction Box Terminal Block Junction Box Cable Color Monitor Bendix Connector P1 Black D 4 Black D Brown B 2 Bro...

Page 19: ...Figure 12 Top View of Pins and Terminal Block 6 Connect the wires from the color coded wire into surge protector terminal screws Route the wires through the bottom of the case under the display and label the wires for channel 1 and 2 and and 7 Temporarily tape the ends of channel 2 wires to avoid the possibility of shorts Connect a milliampmeter to the channel 1 extension leads 8 Plug the screw te...

Page 20: ... 08 mA 10 Adjust mA Output To select Adjust E 11 Enters Adjust 12 Adjust output up or down as need until milliampmeter reads 4 mA 2 3 92 to 4 08 mA E 13 Enters accepts the adjustment 14 Return to channel selection Displays CH1 4 00 mA E 15 Enter Channel selection 16 CH 1 20 0 mA display blinks E 17 Enters CH1 20 0 mA only blinks 18 Milliampmeter displays 20 mA 2 19 6 to 2 04 mA 19 Adjust 20 mA Out...

Page 21: ... 3 RS485 with data logging option The default communications data format is 9600 baud 8 bit word 1 stop bit and no parity Baud and parity can be changed in the COMM menu in the General menu see Table 5 2 8 1 RS232 Communications Monitors with the RS232 with data logging option can dump data to a personal computer PC or a printer connected to the four conductor Din connector at the base of the moni...

Page 22: ...WHT RED BLK GRN TB6 Female DIN Plug attached to monitor s case RS232 Personal Computer Cable Cat Number 16086 Table 2 Serial Communication Conductors TB6 Signal Name Color Mini Din DB9M TB6 1 Busy Black 3 8 TB6 2 Instrument Receive Data Red 1 3 TB6 3 Instrument Transmit Data White 4 2 TB6 4 Signal Ground Green 2 5 ...

Page 23: ...ognized when A B by 200 mV Maximum transmission line length is 4000 ft using shielded 26 AWG twisted pair Belden 9841 Shield connected to signal ground at all terminals RS485 Line Termination Each instrument is shipped with an internal 470 Ω termination resistor R7 This is the proper termination for a network consisting of one host with a standard 120 Ω termination resistor and up to four instrume...

Page 24: ...e Exploded View 2 11 New Membrane Pre qualification Testing The membrane used for the free chlorine probe must be checked for absorbency prior to its installation 1 Fill a cup with tap water 2 Using tweezers gently place a membrane on top of the water surface being careful not to immerse the membrane The membrane must float on top 1 2 3 4 1 1 1 2 2 2 3 3 3 4 4 4 4000 ft Max TB6 Instrument N TB6 In...

Page 25: ...n DO NOT install the spacers When installing the membrane it is best to use clean blunt tweezers to gently grasp the membrane at the edges only This avoids puncturing or soiling the membrane either of which will render the probe inoperable The membrane must be kept wet after removing the probe from the analyte solution 4 Place a new membrane into the membrane holder with tweezers and screw the hol...

Page 26: ... Procedure 16116Install fm Section 2 10 Connect the probe to the monitor and apply power Allow about 12 hours for the displayed reading to stabilize prior to attempting to calibrate the instrument see section 3 13 1 on page 34 ...

Page 27: ...sues 3 2 Front Panel Display and Controls Model 8400 series meters are supplied with a hand held magnet that activates front panel switches when the user touches it to one of four icons on the bottom of the display panel To prevent tampering keep the magnet in a separate location from the instrument Figure 19 depicts the LCD display alarm indicators and icon switches The Check LED indicates a syst...

Page 28: ...renheit or Celsius and Parts Per Million ppm or milligrams per liter mg L chosen as desired see section 3 4 on page 28 Figure 20 Main Screen 3 3 2 Main Menu The Main Menu Figure 21 is the starting menu from which all meter settings and operations are performed This menu is accessed from the Main Screen above by selecting the F icon To enter and configure any of the Main Menu listings see section 3...

Page 29: ...e parameter value will begin to blink Now use the arrow icons to scroll to the desired value When the value has been set activate the icon again to store the new value permanently Activate the F icon to abort the change at any time This will revert to the previous menu to indicate the value has NOT been saved Note that with some parameters such as lfit in the Alarms menu the E icon will cause the ...

Page 30: ...nits F Damping 2 seconds Alarm 1 Sp 2 00 ppm Alarm 1 Rsp 1 00 ppm Alarm 1 Delay 10 seconds Alarm 1 Lfit 0000 Alarm 2 Sp 5 00 ppm Alarm 2 Rsp 2 50 ppm Alarm 2 Delay 10 seconds Alarm 2 Lfit 0000 Check Delay 5 seconds Check Lfit 0000 Vma Ch 1 Units ppm Vma Ch 1 Spn 20 0 Vma Ch 1 Volts 0 1 V dc Vma Ch 1 Ma 4 20 mA Vma Ch 2 Units F Vma Ch 2 Spn 212 Vma Ch 2 Volts 0 1 V dc Vma Ch 2 Ma 4 20mA Gpot 478 Ze...

Page 31: ...ssage indicating the nature of the problem see section 4 7 on page 59 To view the Main Screen use the magnet and select any of the front panel icons Alarm 1 and Alarm 2 are automatically cleared and inhibited in the presence of certain CHECK alarms If Alarm 1 or Alarm 2 is already active during these alarms its state is cleared VMA analog outputs are held at the last reading during system Check A ...

Page 32: ... lfit 0000 0 sec or 1 sec TIME DELAYS A11 A12 A13 VMA CH1 Unit ppm F or C Spn ppm 1 00 to 20 0 F 100 to 212 C 50 to 100 V 1 0 to 1 V 5 0 to 5 V CH2 Unit ppm F or C Spn ppm 1 00 to 20 0 F 100 to 212 C 50 to 100 V 1 0 to 1 V 5 0 to 5 V ADJ Adjust NONE CH1 4 00 mA 20 mA CH1 0 00 V 1 00 V 5 00 V CH2 4 00 mA 20 mA CH2 0 00 V 1 00 V 5 00 V DEC INC SYS Gpot 200 to 511 478 default ADC Non adjustable Reado...

Page 33: ... by the monitor Setting the RNG parameter found in the RDG menu helps optimize gain control during span calibration Settings are 5 10 15 and 20 default Greatest accuracy is obtained when the Maximum Range setting is not set excessively higher than it can be reasonably expected to occur at a specific site For example there is nothing to be gained by setting the Maximum Range to 20 at a site which h...

Page 34: ...idelines are important considerations for fast and accurate calibration of the meter They are particularly important when attempting to SPAN calibrate the meter to concentrations below 1 00 ppm 1 00 mg L 3 13 1 Probe Preparation and Setup Ensure that the probe has been properly prepared and installed If the probe has just been rebuilt connect the probe to the monitor apply system power and permit ...

Page 35: ...rrected drift errors would appear in displayed concentration readings Membrane temperature is monitored by the instrument to compensate for the displayed chlorine readings For this purpose a thermistor is mounted inside the probe body close to the membrane The thermistor resistance is converted into an amplification factor which the software applies to the probe output signal The instrument softwa...

Page 36: ...dure using the icon or acknowledging the complete message using the icon at the end of the sequence A typical zero span calibration screen is depicted in the figure below The scrolling message area provides instructions to the operator during calibration Figure 24 ZERO or SPAN Calibration Menu Items Typical 3 14 Zero Calibration During zero calibration the probe is immersed in a solution free of a...

Page 37: ... DAMP parameter in the RDG menus screen see section 3 22 on page 43 3 When stable select E At this point the timer will set to 10 minutes and begin counting down while the instrument monitors the stability of the probe signal If you have already observed a stable reading as required in step 2 this check will normally take about 2 minutes When the stability check is finished the message Zero Cal Co...

Page 38: ... 15 2 1 Check Maximum Range Setting Ensure that the monitor s Maximum Range has been set prior to performing span calibration For optimum accuracy set the Maximum Range to a value that is not greatly higher than the highest expected concentration For example if the highest expected concentration for the site is 5 ppm it is less effective to set the meters Maximum Range to 20 ppm see section 3 10 o...

Page 39: ...tes and begin counting down while the instrument monitors the probe signal stability These variances must be less than 0 02 ppm over 60 seconds before the instrument will accept the reading as stable This will take at least 60 seconds If the timer expires reach 0 00 an error message will scroll until it is acknowledged by activating any icon Although not recommended you may bypass this phase by ac...

Page 40: ...erate in either normal or fail safe mode A time delay function alarm inhibit and test function are standard features Figure 25 Alarm Configuration Menu To change alarm set points enter the ALM Alarm menu and select either Alarm 1 or Alarm 2 ALM1 or ALM2 Place the menu cursor on Set and select the concentration at which the alarm is to be activated Next place the menu cursor on Reset and select the...

Page 41: ... 17 4 2 Fail Safe Relay Mode f A fail safe relay is selected by entering a 1 under the f in the lfit parameter Fail safe designates the mode of operation for a relay where the relay coil is normally energized and will de energize when alarm conditions are met Conversely Non Fail safe relay Normal operation f value set to 0 is when the relay coil is normally de energized and will energize when alar...

Page 42: ...the selected Spn value Permissible values are ppm 1 00 20 0 in 0 01 increments for values less than or equal to 9 99 and 0 1 increments for values greater than or equal to 10 V Sets the voltage range to either 0 1 V or 0 5 V mA Set the 4 20 milliamp output to normal or inverted The 4 20mA output range may be inverted 20 mA 0 00 4 mA span for operating inverse proportional pumps On systems where mo...

Page 43: ...mal point at either 1 0 0 1 or 0 01 Figure 29 Display Precision Adjustment Range Menu 3 22 Damping Adjustment The variability of the measured and displayed concentration value may be controlled by adjusting the damping value Low values of damping cause the measured concentration value to respond rapidly to rapid changes in concentration higher values slow the response thus damping out rapid fluctu...

Page 44: ...above is more specifically the maximum value of change in magnitude Thus the percent of signal magnitude reached for a given number of time constants is equally applicable to reductions in magnitude as well as increases in magnitude The overall affect of increased damping is a smoothing of the meter s response to changes in concentration Figure 31 Figure 31 Output Damping Relative to Input Example...

Page 45: ...tails the storage capacity of the data logger 3 23 1 SETTINGS Menu Data Log Setup There are two parameters associated with the setup of the data logger under the Settings menu the sampling rate Rate and the on off reset control Ctrl The sampling rate parameter specifies the number of minutes between samples Note that the actual value stored is an average taken over the sampling period The on off r...

Page 46: ...odically it may be desirable to disable data logging To do so change the value of the control parameter to Off To clear the existing data log memory change the value of the CTRL to Rst and activate the icon This will clear out the existing data log memory Note that the value of the CTRL returns to either Off or On whichever was set prior to reset Rst 3 23 4 DATA Menu Viewing Trend Data Log Records...

Page 47: ...the optional logger and communications option have the capability of sending the logged data as a report to an ASCII serial device such as a printer or terminal device A four pin Din connector located at the bottom center of the meter is the serial interface connector for this data transfer The wires connecting this connector to pins 2 and 3 of terminal block TB6 on the power supply board within t...

Page 48: ...trol to Off Another consideration for data logging integrity is what happens when the instrument date time or sampling rate is changed Changing the instrument date does not affect data logging except to change the date of the current series The series is not interrupted only the date associated with the current series is changed However changing the instrument time on the Main Display or sample ra...

Page 49: ...ting the Gpot setting User Entered Cl2 Concentration SPAN calibration Probe Input Signal Level During SPAN Calibration Probe Input Signal During Zero Calibration Max Range Parameter in RDG menu 3 24 2 ADC The Model 8450 measures the amplified probe signal with a 12 bit analog to digital converter and then reports this as the ADC value This value can range from 0 to 4095 and is provided for trouble...

Page 50: ...Page 50 SYS Menu 16116Operation fm Section 3 ...

Page 51: ...remove the Teflon fill screw and observe the tip area for leakage Replace the membrane if leakage is observed The porous properties of the membrane material make it subject to fouling or clogging thus reducing the probe s ability to respond to chlorine Clean the membrane by gently wiping it with a soft moist cloth Care should be exercised while wiping the membrane because this can possibly stretch...

Page 52: ...t the tip 5 Turn the probe over so that the tip is pointing down Then remove the electrolyte fill screw on the side of the canister Tap the probe gently to allow electrolyte to flow down around the new membrane 6 Tighten the three body screws The platinum tip should press out into the new membrane resulting in a smooth stretching of the membrane across the tip Then replace the electrolyte fill scr...

Page 53: ...tion of 50 Nitric Acid about a in depth will suffice Allow the tip to soak in the solution for about five minutes while ensuring that the acid does not come in contact with the silver electrode Rinse the tip thoroughly in distilled water and reassemble the probe Perform system calibration 4 2 3 2 Silver Anode Cleaning Disassemble the probe and immerse the probe s electrodes for 45 60 seconds in a ...

Page 54: ...lly indicates leakage of electrolyte under the probes cathode and will require probe body replacement Figure 37 Probe Plug Conductors 4 3 Resolving Calibration Problems In general most calibration problems can be resolved by allowing enough time for the probe s thermistor and signal output to stabilize to their final levels This is particularly true when the probe is taken out of a cool sample str...

Page 55: ... the reading is settled and stable verify the displayed concentration is lower than the last value entered during span calibration if known If it is higher this may be an indication of the presence of contaminated zero water or an improper earlier calibration If the zero water is known to be chlorine free then attempt to re zero the instrument Do not bypass the stability check 4 If the timer expir...

Page 56: ...d wave E to start the calibration timer After one minute wave the E key and observe the message SPAN CAL COMPLETE If the message PROBE SIGNAL LOW CAL ABORTED appears proceed to step 4 4 If after waiting 20 minutes the concentration has not settled to a stable value of at least 0 02 ppm or if you have observed the error message in step 3 a Recheck the known concentration and pH levels using laborat...

Page 57: ...or messages listed below Follow the directions listed below each message to help isolate and correct the problem 4 6 Calibrating with a Simulated Input This procedure can be used to verify that the monitor is capable of calibrating a probe and should be performed only when a problem with the monitor is suspected Note During this procedure the factory default parameters will be restored Prior to pe...

Page 58: ...ne Monitor Continue to hold the magnet in place until the instrument s sign on screen appears Model Software version etc Remove the magnet 4 Enter the calibration CAL menu and select ZERO calibration When the zero cal complete message appears exit the menu by selecting the icon 5 Adjust the voltage input to 600 mV Span then enter the calibration Span menu Select again and use the icons to adjust t...

Page 59: ...sets parameters back to factory default values and displays this message The message is cleared by activating any of the four front panel icons The operator should then restore desired parameters and readjust any analog outputs that may have been previously adjusted Probe Signal High or Low This message is displayed as long as readings of the probe are too high or too low and thereby cause the inp...

Page 60: ... restored Prior to performing this procedure document the instrument s parameter setting so that they may be re installed later Ensure the all instrument s present parameter settings have been documented then remove AC power from the instrument Next while applying the magnet to the F icon re apply power to the instrument Continue to hold the magnet in place until the instrument s sign on screen ap...

Page 61: ...Free Chlorine Probe each 1675 Flow Cell 3 8 Hose Barb Fitting each 17393 O Ring 5 pkg 16905 Constant Head Overflow Assembly each 17201 Flow Cell Assy includes 17201 each 16369 Accessories Probe Pipe Mounting Kit includes probe cone adaptor and handrail brackets each 16410 Probe Polerizer Specify Free Chlorine Probe each 16239 Junction Box with Receptacle each 16238 Junction Box each 1683 Air Agita...

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Page 63: ...A call 1 800 635 4567 Outside the U S A and Europe send E mail to intltech hach com Repair Service Authorization must be obtained from Hach before sending any items for repair Please contact the Hach Service Center serving your location Hach Company P O Box 389 Loveland Colorado 80539 0389 U S A Telephone 1 800 635 4567 or 970 669 3050 Fax 970 669 2932 By Telephone 800 635 4567 By Fax 970 461 3915...

Page 64: ...il info lange se www lange se Denmark Dr Lange Danmark A S Jernhoolmen 34 40 DK 2650 Hvidovre Tel 45 0 36 77 2911 Fax 45 0 36 77 4911 email drlange drlange dk www drlange de Italy Dr Bruno Lange s r I via Riccione 14 IT 20156 Milano Tel 39 0 2 39 23 14 1 Fax 33 0 2 39 23 14 39 email info drlange it www drlange it Sweden Dr Lange AB LAB Products Box 9008 S 40091 Götebord Tel 46 31 28 50 50 Fax 46 3...

Page 65: ...attempted repair not authorized by Hach Company Any product not used in accordance with the instructions furnished by Hach Company Freight charges to return merchandise to Hach Company Freight charges on expedited or express shipment of warranted parts or product Travel fees associated with on site warranty repair This warranty contains the sole express warranty made by Hach Company in connection ...

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