The RD299 HPT is a combined humidity, pressure and temperature sensor for use with the RD298 & RD398 ShockLog range of recorders. It enables any version of the RD298 or RD398 to monitor an extended range of environmental factors and is fully supported by the ShockLog software. The RD299 HPT has been designed to function reliably in harshest of environments. The electronic components are assembled using surface mount technology and the latest automatic assembly equipment. The complete electronic and transducer package is enclosed in a stainless steel case and bonded to the military quality connector, which provides electrical and mechanical attachment to the RD298 or RD398 ShockLog recorder. This construction technique, in combination with the absence of cables for power or signal results in a very high immunity to electrical interference and very low levels of RF emission. The RD299 HPT may safely be used in close proximity to sensitive instruments or in difficult electrical environments. The RD299 HPT has been designed to meet IP30 and is capable of operating at temperatures between -40 and +85°C. An extension cable is available as an optional extra for applications where the RD299 must be mounted remotely from the RD298 or RD398 ShockLog recorder and through the use of the bulkhead adaptor it is possible to mount the HPT sensor internally while leaving the RD298 or RD398 Shock recorder on the external surface.