Global Water 800-876-1172 • globalw.com Global Water Instrumentation, Inc.
Global Water 800-876-1172 • globalw.com The models 3675 & 3676 are precise instruments for the measurement and control of pH and mV (ORP). Two output relays are provided for ON/OFF control. The isolated 4-20 mA current output covers the input control range of 0 to 14 pH and 0 to 1400 mV. Both models are housed in a rugged 1/4 DIN plastic case. This allows the meters to fit into standard panel cutouts, while providing industrial weatherproof and environmental housings.
Global Water 800-876-1172 • globalw.com I) Inspection a) Your 3675 and/or 3676 1/4 DIN pH/ORP Controller unit was carefully inspected and certified by our Quality Assurance Team before shipping. If any damage has occurred during shipping, please notify Global Water Instrumentation, Inc. and file a claim with the carrier involved.
Global Water 800-876-1172 • globalw.com II) Temperature Compensation a) These meters are designed to be used with a PT-100 RTD temperature probe for Automatic Temperature Compensation operations. The alpha value of PT-100 element is 0.00385. A precision 0.1% resistor can be connected across the ATC input terminals to simulate a fixed process temperature. Table 1 Temperature °C 0 10 20 25 30 40 50 60 70 80 90 100 Resistor value Ω 100.00 103.90 107.79 109.73 111.67 115.54 119.40 123.24 127.07 130.89 134.
Global Water 800-876-1172 • globalw.com reference electrode to the Reference Input terminal. f) Temperature Compensation Input Connections: Using the ATC mode, connect the ATC input terminals. A precision 0.1% resistor can be connected across the ATC terminals to simulate a fixed process temperature. Refer to Table 1 on page 4. IV) Mounting Procedure a) Make a cutout on any panel, with a thickness of 1/16 in (1.5 mm) to 3/8 in. (9.5 mm).
Global Water 800-876-1172 • globalw.com h) Adjust the SLOPE control for the instrument to display the buffer value corresponding to the temperature measured in step 6 (f). Refer to Table 2. i) Remove the pH electrode and ATC probe from the second buffer and rinse with distilled water. The instrument is dual point calibrated and is now ready for measurements. Table 2 - Temperature Cofficient Of The Ph Buffers BUFFERS °C 0 5 10 15 20 25 30 35 40 45 50 55 60 10.01 10.32 10.25 10.18 10.12 10.06 10.01 9.97 9.
Global Water 800-876-1172 • globalw.com VII) Output Load a) Relay Output: The current through the relay output contacts should not exceed 5 Amp at 115V AC and 2.5 Amp at 230V AC in order not to cause permanent damage to the relay contacts. This rating is specified for RESISTIVE loads only. b) Current Output The maximum load is 550 Ω. Output current inaccuracies may occur for load impedance in excess of 550 Ω.
Global Water 800-876-1172 • globalw.com 1. Press the LOW ALARM set point switch .The instrument will indicate the alarm set point value. The alarm set point value can be adjusted by the LOW ALARM set point control. 2. Release the LOW ALARM set point switch. The instrument will indicate the measured process value. 3. The LOW ALARM set point LED will be ON and the LOW ALARM output relay will be energized when the measured value is less than the alarm set point value.
Global Water 800-876-1172 • globalw.com details of the application and installation and any additional pertinent information. b) In the event that the equipment needs to be returned to the factory for any reason, please call to obtain an RMA# (Return Material authorization). Do not return items without an RMA# displayed on the outside of the package. Clean and decontaminate the 3675 and/or 3676 if necessary. Include a written statement describing the problems.
