The spec sheet for the SXT 5HND states that the operating temperature range is -30C to +80C but doesn't state how this is to be measured.

I'm in Qatar where summer air temperatures will break 50C and objects in direct sunlight often are 20C higher, there are cases where exposed metalwork is 30C higher.

If I assume that the specification refers to ambient air temperature then there is no issue, if it refers to surface temperature then I may have a problem as the unit gets warm in operation. If it refers to the internal temperature sensor then I definately have an issue as it typically reads 20-25C above ambient.

Maybe I need to install a sunshield above the units.

Can anyone clarify how this specification value was defined?

Also I'd love to hear about experiences in hot and humid climates with the SXT 5HND. Same for effects of temperature inversion layers on links in the range of 1000-2000m.

Andy

all products are measured at ambient/air temperature in SXT case inside air is ambient.

all products are measured at ambient/air temperature in SXT case inside air is ambient.

Do you mean that you consider the air temp inside the case to be ambient and therefore the product specification is based on the internal temperature of the box which is 20-25C higher than the air outside the box (depending on wind etc). This is different to the definition of ambient temperature for the entire telecommunications and consumer electronics industries[1].

On the basis of your statement the equipment will operate with an external temperature of up to approximately 55C out of direct sunlight and must be derated if it is in direct sunlight to compensate for heating due to sunlight falling on the enclosure.

Did I get this correct? It means that the unit will need a sun shield when used outdoor where is a possibility of the external temperature exceeding about 30C (almost anywhere). This sun shield will cost almost as much as the SXT once it has been designed, manufactured and installed 40M up a comms tower as it has to be designed not to fall and injure a person during a storm.

Andy



[1] This is an important definition and will have an impact on warranty. I think most people would take the industry definition and would say that the equipment fails to meet the published specification.

no, the specified temperature is outside ambient temperature. we put the device inside the temperature chamber, and turn the temperature of chamber to 80C. this would be the equivalent of "in shade" temperature in Qatar.

no, the specified temperature is outside ambient temperature. we put the device inside the temperature chamber, and turn the temperature of chamber to 80C. this would be the equivalent of "in shade" temperature in Qatar.

Thanks for clarifying. This makes a huge difference in deployment as it eliminates the need for a sun shield.

Andy

no, the specified temperature is outside ambient temperature. we put the device inside the temperature chamber, and turn the temperature of chamber to 80C. this would be the equivalent of "in shade" temperature in Qatar.

others would call it "Sauna"

Maybe sauna. Except that ours goes from -120C to +770C