What are the precautions for the use of precision potentiometers?

The precautions for using precision potentiometers encompass several aspects to ensure their proper operation and extended lifespan. Here are the key points translated into English:

Storage and Installation Precautions

1. Storage Environment:
   • Avoid excessive compression when storing precision potentiometers to prevent the adjustment knob from falling off.
   • Keep the storage environment dry to prevent internal components from getting damp.
   • Store the potentiometers away from environments with high concentrations of chemicals such as ammonia, amines, alkaline solutions, aromatic hydrocarbons, ketones, halogenated hydrocarbons, etc., to prolong their service life.
2. Installation Requirements:
   • Use a mounting bracket to secure the potentiometer during installation.
   • Handle the potentiometer gently during installation to avoid damaging the leads.
   • Solder the external wiring to the waist groove of the leads rather than the top to minimize impact on the potentiometer's internal components.
   • Do not disassemble, modify, or remove labels from the potentiometer without authorization, including loosening screws or adjusting the tightening ring position.

Operation Precautions

1. Adjustment Force:
   • Adjust the potentiometer with moderate force to avoid damaging the adjustment knob or causing issues like incomplete closure or jamming.
   • The reverse operation force may become lighter with increasing temperature and tighter with decreasing temperature. Use special low-temperature grease if operating in cold environments.
2. Resistance Adjustment:
   • Do not adjust the resistance of the precision potentiometer arbitrarily to prevent excessive deviation and potential damage due to excessive current.
3. Electrical Parameters:
   • Ensure the applied voltage is within the rated power dissipation range of the precision potentiometer. Reduce power usage at higher temperatures (e.g., above 70°C).
   • Recommended current through the potentiometer is 2mA, with a maximum of 10mA, to prevent overcurrent damage.
4. Grounding and Loading:
   • If present, the grounding lug of the potentiometer must be grounded to prevent external interference.
   • Avoid overloading the potentiometer by operating within its rated values. When using it as a variable resistor, adjust the allowable power dissipation proportionally to the contact brush's travel to ensure the current does not exceed the rated value.
5. Environment and Cleaning:
   • Prevent condensation or water droplets on the surface of the precision potentiometer and avoid using it in humid environments to prevent insulation degradation or short circuits.
   • For non-sealed potentiometers with excessive noise, clean the resistance plate with alcohol-soaked cotton balls instead of applying lubricant. Also, remove oil stains from the contact brush and lead springs.

Other Precautions

1. Synchronization Accuracy:
   • For dual-gang precision potentiometers, the installation structure, dimensions, and test reference points are typically based on the reference gang (first gang). Synchronization accuracy refers to the percentage difference in output voltage between the two gangs at a specific reference point.
2. Accuracy and Linearity:
   • The accuracy of a precision potentiometer refers to the conformity of its output characteristic, not the tolerance of its total resistance. Linear accuracy is measured independently with the load open-circuited.
3. Replacement Principles:
   • When replacing a severely damaged precision potentiometer, it's best to use one with the same model and resistance value. If unavailable, substitute with a similar model and resistance value, considering the allowable resistance variation range and power rating requirements.