The right housing will protect your encoder from caustic environments and corrosive atmospheres, prolong the encoder's life, reduce downtime, and ensure reliable feedback. How do you know when you need a special, corrosion-resistant housing? Ask yourself the following questions:

1. Will the encoder be washed-down with caustic chemicals? Many encoders have aluminum housings that might not hold up to the strongest industrial cleaners. If the machinery the encoders are installed on will be subjected to washdown with caustic chemicals,  a standard housing may not offer enough protection.
    
2. During use, will the encoder come into contact with corrosive agents? Surprisingly, even food products may be corrosive to some materials, so consider what kind of machinery the encoders will be on. Will the encoder have contact with any corrosive material in day-to-day operations, or in the event of a spill? Will the encoder be in the presence of any acids or corrosive chemicals during the operation of the machinery? 
    
3. Are there airborne corrosive agents to consider? Even salty air can cause corrosion. And depending on your industrial environment, there could be even stronger corrosive agents in the air around your machinery and its encoder(s). 
    

What's the solution?

Fortunately, there are corrosive-resistant encoder housings that can solve your problem.

Stainless steel. The old standby, stainless steel is a great solution for many applications. The drawbacks are that it's expensive, it's heavy – which can be a problem, depending on the application – and not every encoder is available with a stainless steel housing.

 

Non-corrosive nylon composite housing. Generally less expensive than stainless steel, non-corrosive nylon composite housings, like the thru-bore encoder pictured at left, may be more widely available for the type of encoders you're looking for. 

In addition to the housing, consider external parts that might be exposed to the corrosive environment, and verify that they are stainless steel or another corrosive-resistant material:
- Connectors 
- Shaft or shaft collar  
- Mounting hardware
- Gland/cable

Finally, consider what IP Rating you might need. If you're not sure, consult WP-2013: What Is an IP Rating, and What Does It Mean?

When purchasing your encoders, be sure to explain what the machinery will be exposed to in day-to-day operation. We will know how to ensure that you get the right housing material on your encoders. 

For more information, consult WP-2006: Encoders in Inhospitable Environments or see Harsh Duty Solutions.