Temperature compensation is a great feature of the PerfectStar focus controllers (excluding PerfectStarLite), but to perform to its full potential the sensor must read the temperature of the telescope accurately and not be influenced by the surrounding air, since they will change at very different rates. That is, the sensor must be thermally coupled to the telescope tube and insulated from the air. This can be done with the standard sensor, but requires some planning an effort on the part of the user. PerfectTemp makes it much easier: Just place the sensor block face down on the telescope tube, secure it in place with the included hook-
The body of the PerfectTemp sensor is made of a plastic with good thermal insulation properties. The electronic sensor is embedded in an aluminum cylinder that protrudes through the face of the sensor and is spring loaded to press firmly against the telescope. The surface of the cylinder is polished to enhance thermal contact and for permanent or semi-
In addition to the insulating properties of the body, the electrical connections to the sensor are made with very thin wires to reduce heat transfer through the wires. The data cable (3 feet in length) is permanently attached to the sensor and plugs directly into the focus motor unit at the other end.
The included hook-
Precision: better than 0.1 degree C
Absolute accuracy: +/-
PerfectTemp is based on the same integrated circuit as the standard temperature sensor and connects to the 1/8” stereo phone jack on PerfectStar and PerfectStar SCT motors. Customers using the PerfectStar Focus Controller with motors from other manufacturers will need a custom-
PerfectTemp Sensor: $40 (with strap for up to 9” diameter)
Additional strap length: $1 per foot
Custom cable: Please contact Wa-
PerfectTemp is generally available from stock.