Weighing balance

Measurement of the weight of an object is carried out using laboratory scales. Using a set of $7$ weights weighing $1$ g, $3$ g, $9$ g, $27$ g, $81$ g, $243$ g and $729$ g, you can measure the weight of any item with a whole weight from $1$ to $1093$ g in a single way. For example, to measure an object weighing $4$ g, you need to put weights of $1$ and $3$ g on one bowl, and on the other the object itself. For an object weighing $68$ g add to the cup with it the weights of $1$, $3$ and $9$ g, and on another cup - put the weight of $81$ g.

Determine how many weights from this set should be used to weigh an item of a given weight.