The engrammeter is an item given to the player by Kharshai to collect Mahjarrat Memories, charged by 500 Divine memories of Vibrant or higher. It is used in the Mahjarrat Memories miniquest, starting out depleted but becoming charged as memories are collected. When players ask about the engrammeter, Kharshai will admit that it is the strange chest that held his memory gem from Koschei's Troubles, recycled for use in containing other memories.
After the player brings all 15 memories to Kharshai, he will state that the Engrammeter might be useful on Freneskae if the player is ever able to go there. As such, a fully charged Engrammeter will become a Distorted engrammeter, but will provide some damage reduction while on Freneskae. This also rewards the player with 25,000 Divination exp.
Trying to operate the charged engrammeter at Port Khazard or the Fight Arena will not give you the usual message when there is no memory to be found, but instead your character will say "Nothing here. Khazard must be too young to have left a memory." Likewise, using it at Zamorak's camp from the Battle of Lumbridge will produce "Nothing here. It must not work on gods or half-Mahjarrat."
The Engrammeter can only hold up to 500 memories. Also, the engrammeter cannot be recharged after use until the memory it found has been delivered to Kharshai.
The Engrammeter can only be converted to a Distorted engrammeter in the area of Freneskae visited during Fate of the Gods. Trying to look for a memory in the area of Freneskae visited during Children of Mah will yield a message of the engrammeter being unable to detect anything.