Specifications

• Input voltage range ±2 volts
• Input impedance > 10exp(12) Ohm
• Input bias current 1 pico amp typical
• Output polarity jumper selectable
• Zero offset < ±15 mv typical
• Voltage gain 1.0 adjustable
• Dimensions 36 mm x 50 mm

Instructions

When hooking up the model 66 pre-Amplifier to a Jenco Controller both a resistor of approximately 3K ohms, (or a 3K ohm Balco ATC installed in the pH electrode), must be attached to the Pre-Amplifier between connectors 4 & 5 and a second resistor of approximately 100 ohms, (110 ohms = 25°C/ 79°F), must be connected to the 3675/3676 controllers ATC connectors.

The shielded 5 or 6-conductor cable, (Belden 8724 5-conductor, shielded low capacitance cable or McMaster-Carr 6-conductor, shielded, low capacitance cable part # 75985K63) must be attached to the Reference/Ground, connector 5, on the pre-Amplifier to shield against noise.

Do not also attach the reference ground to the controller reference ground but leave this unconnected. This prevents a loop being formed that could add noise to the system.

The positive and negative 5 to 8 volts DC must also be supplied. From either the controller or a separate DC power supply for the model 66 Pre-Amplifier to work.