Dear Customer, Thank you for choosing a Hanna Instruments Product. Please read this instruction manual carefully before using the instrument. This manual will provide you with all the neces- sary information for the correct use of the instrument, as well as a precise idea of its versatility in a wide range of applications.
Dealer in their original packing. GENERAL DESCRIPTION HI 8666 is a 2-wire, 4 to 20 mA relative humidity and temperature transmitter. The instrument transmits electrically isolated out- puts that are linear and proportional to RH% and °C.
SPECIFICATIONS Range 0 (4 mA) to 100% (20 mA) °C -20 (4 mA) to 60°C (20 mA) Resolution ±0.125% RH, ±0.02 mA °C ±0.1°C, ±0.02 mA Accuracy ±2% RH (5 to 80% RH) ±4% RH (80 to 90% RH, 0 to 40°C) °C ±1% of span Typical EMC RH...
TERMINAL BOARD AND INSTALLATION The HI 8666 Transmitter has an 11-pin con- nector at the rear of the instrument. Connect it to a UNDECAL relay socket. The terminals are: 1 +°C: Positive Terminal; 9 -°C: Negative Terminal; 4 +RH: Positive Terminal;...
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2. Passive and not isolated receivers (Common positive) °C • Receiver Receiver • • • • • Power °C Supply Transmitter Transmitter • • • 3. Passive and not isolated receivers (Common negative) • °C Receiver Receiver • • • •...
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4. Active receivers (both isolated or not) • • Transmitter Receiver • • • • °C °C Receiver Transmitter • •...
For an accurate annual recalibration, con- tact your nearest Hanna Service Center. You can also check the status of your HI 8666 by using the Hanna mini-calibration cham- bers HI 7102. The kit includes two thermally...
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• When the salt has dis- solved completely, add all the content of the second bottle of HI 7111. • Allow the solution obtained to cool, and then pour it into the chamber marked "RH 11.1%", making sure that no residue remains on Na Cl the walls of the glass con- Li Cl...
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0.0% RH. All RH to mA conversions can be made with the tables provided (see page 12). • Remove the HI 8666 from the chamber and tightly seal the chamber containing the LiCl solution. • Remove the cap from the "RH 75.4%"...
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• Wait for the measurement to stabilize (approximately 4 hours) • Insert the probe in the "RH 75.4%" cham- ber, the multimeter reading should be 16.06 mA: this represents the theoretical chamber value of 75.4% RH. • The relative humidity calibration check- ing procedure is complete.
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Connect the unit to a 12 to 24VDC power supply and hook up a multimeter (range of 20mA) in series with the circuit. • Place the HI 8666 into a stable tempera- ture environment of 25°C, preferably a temperature chamber, and wait for the temperature to stabilize.
ACCESSORIES HI 7102 Mini-calibration RH chamber, complete with O-ring and pre- calibrated saturated salts (LiCl and NaCl) HI 7111/P Spare saturation salts 6 x 15 g bottles of LiCl for low range humidity calibration HI 7121/P Spare saturation salts 6 x 33 g bottles of NaCl for high humidity calibration HI 7164...
WARRANTY HI8666 is warranted for one year against defects in workmanship and materials when used for its intended purpose and main- tained according to instructions. This warranty is limited to repair or replace- ment free of charge. Damages due to accidents, misuse, tamper- ing or lack of prescribed maintenance are not covered.
Hanna Instruments Srl V.le delle industrie 12 35010 Ronchi di Villafranca (PD) ITALY herewith certify that the RH/°C transmitter HI 8666 has been tested and found to be in compliance with the following regulations: IEC 801-2 Electrostatic Discharge IEC 801-3...
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