Instruction Manual QUICK GUIDE • Wiring Diagram Page 2-5 • Programming the Display Page 14• Calibration Chapter 6 • Troubleshooting Chapter 7 Model 14 pH/Redox Transmitter Doc No. L2551 11/00 19 Thomas, Irvine, California 92618 USA Call Toll-Free: 877.246.7900 (USA & Canada) Phone: 949.452.1112 Fax: 949.452.1114 E-Mail: sales@broadleytech.
Model 14 pH/Redox Transmitter Broadley Technologies Corporation 19 Thomas Irvine, California 92618 USA Corporate Headquarters: Toll-Free: 877.246.7900 Tel: 949.452.1112 Fax: 949.452.1114 E-Mail: sales@biotechcatalog.com Website: www.biotechcatalog.
Model 14 pH/Redox Transmitter Table of Contents Chapter 1: Introduction .....................................................................................................................1-1 1.1 Introduction..............................................................................................................................................1-1 1.2 pH Measurement ......................................................................................................................................
Model 14 pH/Redox Transmitter Table of Contents (Continued) Chapter 4: Programming the Instrument (continued)........................................................................4-1 4.5 SERVICE Menu (continued).................................................................................................................4-15 4.5.6 DEFAULT VALUES Menu ...............................................................................................................4-20 4.5.7 ADJUST mA Menu ...............
Model 14 pH/Redox Transmitter Chapter 1: Introduction reference electrodes R = gas constant The Model 14 pH/Redox transmitter has been designed T = temperature in Kelvin for measuring and continuously controlling pH or a[H+] = activity of the hydrogen ion (assumed to redox potential and temperature in industrial process. be equivalent to the concentration of hydrogen ions) F = Faraday constant 1.
Model 14 pH/Redox Transmitter for aOx = a Red and for pH = 0 which correspond to a Consumption standardized hydrogen ion activity a[H+] = 1 mole per liter. The stability and reversibility of a redox system Measuring Ranges strongly influence the reproducibility of the measured redox potential. 1.4 Main Features of the Instrument 2.5 mm2 screw terminal pulledout for the relays and power supply Weight 2 kg Sensor interrogation is a standard feature on the Model 14.
Model 14 pH/Redox Transmitter 1.5 Dimensions (Dimensions are in mm [inches]). 144 mm 5.669" 24 mm 0.945" Esc 28 mm 1.102" 2 Pg13 Enter 73 mm 2.874" 144 mm 5.669" 117 mm 4.606" 24 mm 0.936" 33.5 mm 1.
Model 14 pH/Redox Transmitter 1-4
Model 14 pH/Redox Transmitter Chapter 2: Installation of the Instrument 2.1 Unpacking the Instrument 2.2 Installation Requirements The analyzer should be unpacked with great care. The analyzer should be located in a site, which permits Watch for any loose accessories. Confirm the instru- access for inspection or maintenance operations. ment includes: instruction manual, certificate of con- Choose a site which meets the following criteria: formity, 4 cable glands, 2 fittings and 2 mounting screws.
Model 14 pH/Redox Transmitter 8 mm (0.315”) max. Panel mounting Panel cutout: 138 mm x 138 mm (5.4” x 5.4”) Front panel dimensions: 144 mm x 144 mm (5.7” x 5.7”) Included hardware: 2 flat head screws, 4 mm x 18 mm long, for panels up to 6 mm thick 285 mm (11.22”) max. (a) Wall mounting Included hardware: (a) 2 pan head screws, 4 mm x 60 mm long for red clamping bow Additional required hardware: (b) 2 flat head screws, 4 mm x 60 mm long 80 mm (3.15”) on center 2-2 80 (3.
Model 14 pH/Redox Transmitter Vertical pipe mounting Included hardware: 2 pan head screws, 4 mm x 60 mm long for red clamping bow 42 mm (1.653") max. 320 mm (12.598") max.
Model 14 pH/Redox Transmitter 2.4 Electrical Connections ■ Model 14 Do not switch the instrument on until completion of the installation. An aluminum armor plate inside the Model 14 gives a detailed description of the different terminals and their connections: ➯ The Relay and Main Power terminals represented on the right side are accessible by removing the aluminum plate. Preamp. Supply + l1 S1 Relays + l2 S2 S3 / Sys.Alarm RX / TX + RX / TX S4 / Timer Temp + Temp Input GND Ref. GND Liq.
Model 14 pH/Redox Transmitter 2.5 Terminal Descriptions + + 1 2 RS485 (option) Analog Outputs 0/4 - 20 mA outputs galvanic insulation pH module RX/TX+ RX/TX- Temp+ TempInput Ref.
Model 14 pH/Redox Transmitter 2.6 Power Connection 2.7 Measuring Line For safety reasons, it is required to observe the precau- The Model 14 transmitter should be connected to an tions below: electrode via a shielded cable. 1. The instrument should be connected to the power 2.8 Starting the Transmitter supply by means of a breaker located close to the instrument and clearly identified. Before switching on the transmitter, make sure the site voltage corresponds to the instrument voltage indicated 2.
Model 14 pH/Redox Transmitter 2.10 Changing the Programming Language The default programming language is English. To change the language, follow the procedure below (example for French): MENU 6.86% 23.2°C Disp2 CALIBRATION MAINTENANCE PROGRAMMING SERVICE pH Select Menu Enter SERVICE DISPLAY Enter RESOL.: 0.1pH TEMP.: °C LANGUAGE: GB Select AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. ADJUST mA CONFIGURATION Select DISPLAY DISPLAY CONC: ppm TEMP.: °C PRESSURE: mmHg LANGUAGE: F CONC: ppm TEMP.
Model 14 pH/Redox Transmitter 2-8
Model 14 pH/Redox Transmitter Chapter 3: Front Panel Displays 3.
Model 14 pH/Redox Transmitter 3.2 Displays 1 to 4 (live displays) S1 6.86 S3 23.2°C : temperature measurement S1...S4 : alarm status (invisible if alarm is inactive) pH S2 S1 23.2°C Disp2 Menu S1: ˚C >30.0 S2: OK S3: pH >14 S4: Not Used Disp3 Main Impedances Glass Reference Main 3-2 S4 S3 S1...S4 : alarm status In this case relays S1 and S3 are active Main I1: Measure 4.9 mA I2: Temp Disp4 6.86% : pH measurement (or MV for redox) Analog output allocation and level.
Model 14 pH/Redox Transmitter 3.3 Description of the Function Keys The function keys vary depending on the menu.
Model 14 pH/Redox Transmitter 3.5 Enter or Modify a Value The highlighted digit can be modified with the key . Each digit can be validated by pressing ENTER. Repeat both operations for each digit. 03.89 ppm Increase the digit value 13.89 ppm Enter Validate the digit value 13.89 ppm 15.89 ppm 15.89 ppm Enter Enter 15.89 ppm 15.39 ppm Enter 15.39 ppm 15.37 ppm Enter 15.37 ppm To change the unit 15.
Model 14 pH/Redox Transmitter Chapter 4: Programming the Transmitter 4.1 Main Menu S1 S3 6.86% 23.2°C S2 pH Disp2 Menu S4 MENU CALIBRATION MAINTENANCE PROGRAMMING SERVICE Select CALIBRATION pH. CALIB. TEMP. CALIB. MAINTENANCE 6.98 pH PARAMETERS 23.2°C Select Page 4-2 PROGRAMMING MEASURE ALARMS CONTROLLER mA OUTPUTS RS485 Select Page 4-3 Page 4-4 SERVICE IMPEDENCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL.
Model 14 pH/Redox Transmitter 4.2 CALIBRATION Menus Before any calibration, confirm that the parameters are correctly configured in the MEASURE Menu, page 4-5. All calibrations should follow the procedures below: 1. Configure the calibration characteristics in the “PROGRAMMING” menu. 2. Perform the calibration via the “EXECUTION” menu. An access code may be required if it has been programmed. See page 4-19 for CODE menu.
Model 14 pH/Redox Transmitter Parameters Date mm/dd/yy Date of last calibration. This must be updated manually. SLOPE XX.X% The slope of the sensor Off. X.XX pH The sensor offset 4.3 MAINTENANCE Menu MAINTENANCE 6.98 pH 21.6 ˚C Used for any maintenance operation in the instrument. The transmitter continues to display the variables measured. The relay status is not modified. The relay status is not modified. The analog output value depends on the configuration in the mA OUTPUTS/SPECIAL PROG.
Model 14 pH/Redox Transmitter 4.4 PROGRAMMING Menu An access code may be required. See page 4-19 for CODE menu. PROGRAMMING MEASURE MEASURE ALARMS CONTROLLER mA OUTPUTS RS485 ELECTRODE TEMP. COMP. Select mA OUTPUTS OUTPUT 1 OUTPUT 2 SPECIAL PROG. TEST Select Select ALARMS ALARM 1 ALARM 2 ALARM 3 ALARM 4 Select CONTROLLER CONTROL: Yes MODE: Pulse SETPOINT: 7.00 pH NEUT. Z.: 2.0 pH INERTIA: 000 s REG. MAX.
Model 14 pH/Redox Transmitter 4.4.1 MEASURE Menu PROGRAMMING MEASURE ALARMS mA OUTPUTS RS485 Select MEASURE Enter ELECTRODE TEMP. COMP. Enter Enter Select TEMP. COMP. MEASURE: Yes TYPE: Manual TEMP: 020.0˚C COMP.: Coeff. pH: 0.010 pH Select ELECTRODE TYPE: Other ISO Pt: 1.
Model 14 pH/Redox Transmitter Temperature Compensation MEASURE -No -Yes Select temperature measurement with or without a Pt100/Pt1000 TYPE -Auto -Man Choose automatic or manual temperature compensation TEMP. -XX.X ºC Enter the sample temperature during manual compensation COMP. -NERNST -Pure -Matrix 1 -Matrix 2 -Matrix 3 -Matrix 4 -Coeff. ∆pH 4-6 -XX.XXX Choose the type of curve to be used to calculating temperature compensation • linear compensation (0.
Model 14 pH/Redox Transmitter 4.4.2 ALARMS Menu Relays S1 through S4 may be allocated to the limit, alarm system or timer functions. When the controller function is activated, Alarms 1 and 2 are neither displayed nor accessible. See page 4-10 for CONTROLLER menu.
Model 14 pH/Redox Transmitter ➯ SYSTEM ALARM FUNCTION: Relays S3 and S4 may be used as a fault indicator. To control the faults traced by the analyzer, connect the appropriate relay to an external alarm system. The relay is activated as soon as a default appears. In case of a manual acknowledgment, the relay remains activated even if the default disappears. Press ENTER to deactivate the relay and the error message.
Model 14 pH/Redox Transmitter ➯ TIMER FUNCTION: The S4 relay may be configured to a timer function. Note: The measurement cycle lasts 4 seconds. MODE -No -Limit -Timer The Alarm 4 may be a limit (see parameters above) or a timer function for probe cleaning with Alarm 3 INTERV XXXX Interval between 2 active cycles (in minutes) IMPUL. Nb.
Model 14 pH/Redox Transmitter 4.4.3 CONTROLLER Menu CONTROLLER PROGRAMMING RELAY S1 CONTROL: Yes MODE: Impulse./Freq. SETPOINT: 7.00 pH NEUT. Z.: 2.0 pH INERTIA: 000 s REG. MAX.: 120s RELAY S1 RELAY S2 MANUAL MODE MEASURE ALARMS CONTROLLER mA OUTPUTS RS485 XP1 COEF.: 100% T1: 2.00s S1 MIN: 1.0s EXPONENT: 01.0 Select Select Select MANUAL MODE RELAY S2 7.00 XP2 COEF.: 100% T2: 2.00s MIN: 1.0i/min MAX: 200i/mn pH 25.
Model 14 pH/Redox Transmitter CONTROLLER CONTR. SETPOINT NEUT.Z INTERIA -Yes -No -Pul./Frq. -Frq./Pul. -PULSE -Frq. XX.XX pH XX.X pH XXXs REG.MAX. S1/S2 MIN XX XXX MODE Option to use the controller Choose between controlling by impulse or by frequency or both Setpoint value Zone around setpoint where the regulation is not activated.
Model 14 pH/Redox Transmitter 4.4.4 mA OUTPUTS Menu The analog output signals allow the transmission of the measurements from the analyzer to any external control system. It is highly recommended to use shielded cables for the output signals. This shielding should be connected to the earth terminal on the armor plate. PROGRAMMING MEASURE ALARMS CONTROLLER mA OUTPUTS RS485 mA OUTPUTS OUTPUT 1 OUTPUT 2 SPECIAL PROG. TEST Select Enter Enter Select OUTPUTS 1/2 SPECIAL PROG. MAINTENANCE CALIBRATION SYST.
Model 14 pH/Redox Transmitter Output 1/2 AFFECT LOWER - pH - °C / °F 0/20 4/20 XXXX Lower limit value UPPER XXXX Upper limit value SPECIAL PROG. TYPE Choice of the analog output to measure pH or temperature Choice of the analog output type Special Prog.
Model 14 pH/Redox Transmitter RS485 N° BAUD PARITY BIT STOP 4-14 XX - 300 - 600 - 1200 - 2400 - 4800 - 9600 - No - Odd - Even -1 -2 MONEC number (0–32) Transmission speed in baud Without parity bit With odd parity bit With even parity bit 1 bit stop 2 bit stop
Model 14 pH/Redox Transmitter 4.5 SERVICE Menu SERVICE IMPEDENCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. ADJUST mA Select IMPEDANCES GLASS REFERENCE FREQ. 24.0h TEST Select AVERAGE AVERAGE: 9 TEST ADJUST mA OUTPUT 1 OUTPUT 2 Select SOFT ISSUE MONEC 9135 pH 0.01 Select SOFT ISSUE RESOL.: 0.01 pH UNIT: ˚C LANGUAGE: GB Select SOFT ISSUE CALIB.: 0000 PROG.
Model 14 pH/Redox Transmitter 4.5.1 IMPEDENCES Menu WARNING! An access code may be required. See page 4-19 for CODE Menu. SERVICE Enter IMPEDANCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. mA ADJUST IMPEDANCES GLASS REFERENCE FREQ. 24.0h TEST Select Enter Enter Select GLASS Enter GLASS: Yes LOWER: 0001 MΩ UPPER: 1000 MΩ Select REFERENCE REF.: Yes LOWER: 0001 kΩ UPPER: 1000 kΩ Select 4-16 TEST GLASS 152.5 MΩ REFERENCE 52.
Model 14 pH/Redox Transmitter 4.5.1 IMPEDENCES Menu (Continued) The glass electrode impedance measurement is compensated to 25˚C. This menu defines the lower and upper limits of the electrode impedances for the default detection, which should be defined experimentally. I IMPEDENCES Glass/ Reference FREQ. LOWER UPPER TEST -Yes Allows and impedance measurement -No XXXX h Define the impedance measurement frequency (limits: 0.1 H to 24 H) XXXX mΩ Defines the lower limit for the impedance measurement.
Model 14 pH/Redox Transmitter 4.5.3 DISPLAY Menu DISPLAY SERVICE IMPEDANCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. ADJUST mA Enter RESOL. : 0.01 pH UNIT : °C LANGUAGE : GB Select Select Display RESOL TEMP. - 0.01 pH - 0.
Model 14 pH/Redox Transmitter 4.5.4 CODE Menu Protection codes may be programmed for access to the PROGRAMMING, CALIBRATION, SERVICE menus. This code may be deactivated by entering 0000. CODE SERVICE IMPEDANCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. ADJUST mA Enter CALIB.: 0000 PROG.: 0000 SERVICE: 0000 Select Select Code CALIB. PROG.
Model 14 pH/Redox Transmitter 4.5.5 SOFT ISSUE Menu This menu displays the software version installed in the instrument. SOFT ISSUE SERVICE IMPEDANCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL. ADJUST mA Enter Model 14 pH 1.00 Select 4.5.6 DEFAULT VALUES Menu DEFAULT VAL. Loading Default Values? Yes 4-20 Pressing YES will load the default values. The current programmed values, historic values and calibration parameters will be lost.
Model 14 pH/Redox Transmitter 4.5.7 ADJUST mA Menu The analog output signals are factory-adjusted (upper limit: 20mA). However, if the upper limit of one of the outputs, drifts, the span value can be adjusted with the mA ADJUST menu. Connect an ampere meter in series to the analog output terminals. Adjust the value until the ampere meter displays 20mA. SERVICE IMPEDANCES AVERAGE DISPLAY CODE SOFT ISSUE DEFAULT VAL.
Model 14 pH/Redox Transmitter 4-22
Model 14 pH/Redox Transmitter Chapter 5: Redox Programming Warning ! An access code may be required in programming mode (See page 4-19). Before programming a redox calibration, check the type of electrode to be programmed, select redox in the electrode menu. The Model 14 transmitter must first be configured for redox before calibration is begun. 5.
Model 14 pH/Redox Transmitter CALIBRATION REDOX CALIB. TEMP. CALIB. PARAMETER Enter Select ETALON. REDOX EXECUTION PROGRAMMING Follow the pH calibration procedure on page 6-1. Enter Manual or Process Select Note: The unit of measure for redox calibration is mV.
Model 14 pH/Redox Transmitter Chapter 6: pH Calibration 6.1 Calibrating the Instrument Confirm the parameters in the MEASURE Menu (page 4-5) are correctly configured before performing any calibration. An access code may be required if it has been programmed. (See page 4-19) CALIBRATION Enter pH. CALIB. TEMP. CALIB.* Enter PARAMETERS Select pH. CALIB. Enter TEMP. CALIB. EXECUTION PROGRAMMING Select EXECUTION PARAMETERS DATE: 01/01/98 SLOPE: 97% Select OFF: 0.03 pH T: 0.
Model 14 pH/Redox Transmitter 6.2 Temperature Calibration The pH of a buffer solution depends upon the temperature. Consequently, nominal pH values are reference to 20˚C. Refer to the buffer tables from the manufacturer to determine the pH of the solution at a specific tem- perature. The temperature of the buffer solution needs to be entered only when operating in the manual mode. The temperature element should be calibrated before performing any pH measurement. CALIBRATION Enter pH CALIB. TEMP. CALIB.
Model 14 pH/Redox Transmitter 6.3 pH CALIBRATION Options PROGRAMMING UTILIZATION Automatic Calibration pH CALIB. TYPE: Auto To be used ONLY when calibrating with 2 of the 3 standard buffers (4.00/6.88/9.22) programmed in the transmitter. The user does not have to enter a value when calibrating 2-Point Calibration pH CALIB. TYPE: 2 pts BUF1: 3.75pH BUF2: 8.05pH To be used when calibrating with buffers other than 4.00, 6.88 or 9.22.
Model 14 pH/Redox Transmitter 6.3.1 Two-Point Calibration If automatic temperature compensation has been selected, immerse the ATC probe in the same calibration solution as the electrode. pH CALIB. BUFFER 1 Press ENTER Immerse the electrode in the first buffer. pH CALIB. 6.98 pH Press OK when the reading is stable. Press ESC to leave the menu without saving changes. Change the displayed valued if necessary. 20.3˚C OK pH CALIB. 6.98 06.98 pH pH Repeat these steps for Buffer #2. pH CALIB.
Model 14 pH/Redox Transmitter Chapter 7: Error Messages In manual mode, to supress an error message press ENTER after correcting the default. ERROR MESSAGES 10.8 DESCRIPTION Sensor is not connected correctly. Temperature sensor damaged, replace it if necessary. pH Pt100/Pt1000 SHORT CIRCUIT 11.4 Sensor is not connected correctly. Temperature sensor damaged, replace it if necessary. pH Pt100/Pt1000 OPEN CIRCUIT The pH value is below 3 pH. 1.4 pH MEASURE TOO LOW 13.
Model 14 pH/Redox Transmitter ERROR MESSAGES 7.9 pH DESCRIPTION The glass electrode impedance is below the limits set by the user: - change the limits - replace the electrode, it is probably broken GLASS IMPED. TOO LOW 10.1 pH REF. IMPED. TOO LOW 6.4 pH REF. IMPED. TOO HIGH 5.8 pH REGULATION TOO LONG 7-2 The reference electrode impedance is below the limits set by the user. - change the limits - electrode is damaged, replace it.
Model 14 pH/Redox Transmitter Error messages during a calibration Press ESC to leave the menu and calibrate again. PH CALIB. SLOPE: 99.9% ZERO: 4.00 pH The zero shift is above the limit programmed. Limits : - pH calibration : ±3 pH - redox calibration : ± 250 mV REGULATION TOO LONG SLOPE: 130% ZERO: 0.1 pH The slope shift is above the limit programmed. Limits : 70–120 % SLOPE OUT OF LIMITS PH CALIB. ∆T:-20.0 ˚C ∆T OUT OF LIMITS The temperature drift is above the limit programmed.
Model 14 pH/Redox Transmitter 7-4
Model 14 pH/Redox Transmitter Chapter 8: Impedance Measurement 8.1. Electrode Impedance: Electrode Integrity Index A method generally used to detect an electrode default is to calibrate a pH measurement system in buffer solution. If the slope or the zero (asymmetry) characteristics are out of the programmed limits, one of the electrodes is considered to be damaged. Another method consists of the manual measurement of both electrode impedances.
Model 14 pH/Redox Transmitter 8-2
Model 14 pH/Redox Transmitter Appendix 1: Technical Specifications Operating Conditions ATING CONDITIONS Ambient Temperature Relative Humidity -20˚C to +60˚C 0 – 90% Measure ME Display Range 0 – 14 pH (Can measure down to -3 pH) -1500 mV – 1500 mV -20˚C to 200˚C (- 4˚F – 392˚F) Display Resolution 0.01 pH / 0.1 pH (adjustable) 1 mV 0.1˚C Repeatability ±0.02 pH ±1 mV ±0.
Model 14 pH/Redox Transmitter Calibration IBRATION Calibration Type Slope Matching - 2 points (automatic) - 2 points (manual) - 1 point process 41 to 71 mV @ 25˚C 70–120 % Zero Matching ±3 pH ±250 mV Temperature Calibration - 50˚C to +20˚C (- 90˚F to +36˚F) Controller Setpoint Neutral Zone Programmable in the range 0–14 pH or -1500 mV to +1500 mV Programmable from 0–3 pH or 0–200 mV symetric around the Regulating point Proportional Band Periodicity Programmable from 0 to 500% Programmable from 3
Model 14 pH/Redox Transmitter Alarms ARMS Number of Alarms Function 4 Limits Alarm System Timer Hysteresis Temporization Breaking Power (ohm overcharge) Response Time Relaxation Time 0 to 10% 0 to 999 s 250 V AC, 5A max 100 V DC, 0.7A max 10 ms 5 ms RRS485 S485 Baud Rate Insulation Station Number 300 ...
Model 14 pH/Redox Transmitter Mechanical Characteristics Dimensions Weight Material Specification Mounting Types Cable Glands A-4 144 mm x 144 mm x 150 mm (5.7” x 5.
Model 14 pH/Redox Transmitter Appendix 2: Default Values Calibration pH CALIB. TYPE : Auto PARAMETERS DATE :01/01/96 SLOPE :100.0% OFFSET : 0.00 pH ˚T : 0.0 ˚C PROGR Programming AMMING MEASURE ELECTRODE TYPE : Glass TEMP. COMP. MEASURE : No TEMP. : 25 ˚C COMP. : Nernst ALARMS ALARMS S1/S2/S3/S4 AFFECT. : pH LIMIT : 0.00 pH DIR. : Down DELAY : 000 s HYST. : 00% RELAY : NO mA OUTPUTS OUTPUT 1 AFFECT. : pH TYPE : 0-20 LOWER : 00.00 pH UPPER : 14.00 pH OUTPUT 2 AFFECT. : pH TYPE : 0-20 LOWER : 00.
Model 14 pH/Redox Transmitter RS485 No : 0 BAUD : 9600 PARITY : Non BIT STOP : 1 SERVICE Service IMPEDANCES FREQUENCY : 24.0 H GLASS GLASS : No REFERENCE REFERENCE : No AVERAGE AVERAGE : 0 DISPLAY DISPLAY RES. : 0.01 pH UNIT : ˚C LANGUAGE : GB CODE CALIB. : 0000 PROG.
Model 14 pH/Redox Transmitter Appendix 3: Temperature Conversion Chart • Conversion from ˚C into ˚F : • Conversion from ˚C into ˚K : ˚F = 1.8 x ˚C + 32 ˚K = ˚C + 273.15 ˚C ˚F ˚K ˚C ˚F ˚K 0 32 273.15 23 73.4 296.15 1 33.8 274.15 24 75.2 297.15 2 35.6 275.15 25 77 298.15 3 37.4 276.15 26 78.8 299.15 4 39.2 277.15 27 80.6 300.15 5 41 278.15 28 82.4 301.15 6 42.8 279.15 29 84.2 302.15 7 44.6 280.15 30 86 303.15 8 46.4 281.15 31 87.8 304.15 9 48.
