The Oyster is supplied with an IP67 rated housing. Care needs to be taken when sealing the housing, to ensure that:
- The IP67 rating is maintained
- The housing is not cracked due to overtightening - overtightening will drive the screws too deep into the holes, cracking them.
- Electronic components are not damaged by Electrostatic Discharge (ESD)
As the final sealing of the product is not done by Digital Matter, the manufacturer's warranty does not cover water ingress. It is up to the reseller to ensure that the devices are sealed correctly.
The following process/recommendations are given:
- Consider any necessary anti-static precautions (e.g. a grounded wrist strap) to avoid ESD damage.
- Ensure that the clear silicon seal is in good condition, is lying flat, and is not fouled by any plastic debris or other material.
Close the housing, and gently squeeze it shut. Foam on the lid will compress against the batteries, holding them firmly in place.
The screws used are Posi-Pan head screws, ensure that you have a screwdriver of this type.
Tighten the 6 screws evenly, to a uniform tightness. On the first assembly, the screws may be quite stiff. No threads are cut, so the first insertion cuts the threads.
It should be clear when the screws are tightened sufficiently - the base will sit close to flush with the lid, and there will be pressure on the silicon seal - this is what maintains the water tightness. The base will feel secure against the lid, press gently downwards on the lid, it should not move about more than 1-2mm. The base and lid may not be perfectly flush at mounting tabs - as at the extreme edges there is limited support from the screws - this should not be an issue.
Digital Matter has conducted tests - and found that once hand tightened in this manner, the torque on the screws was 0.7Nm. A screwdriver with a torque limiting clutch set to this value can be used to aid in getting consistent results. However there may be variances due to the stiffness of the screws (on first sealing), variances between torque screwdrivers, or the manner in which they are tightened. Use your discretion
If you are unsure, consider sealing 1 unit by hand, and then measure the torque with your screwdriver - and use this for the remainder to acheive consistent results (this doesn't mean it is the right consistent result)
Or seal the housing without the device inside - make note of how it looks, and then immerse it in water. Note when resealing with the device inside, screw torque will be slightly different as the batteries are now pressing on the lid. However this will be a good guide to determine visually how the housing should fit together.