The instrumentation assembly is for use in an Exercise Head Mark 85. It is of a Type I, Type II, or Type III configuration. Type I configuration is used in Exercise Head Mark 85 Mod 0 (Fleet). Type II configuration is used in Exercise Head Mark 85 Mod 1 (Proofing). The Type III configuration is used in Exercise Head mark 85 Mod 2 (Fleet).

Type I Instrumentation Assembly is for fleet use and provides the necessary interconnecting wires between the exercise head cables, Oscillograph and Logic assembly. Also provided are the necessary processing signal conditioning circuitry. Type II Instrumentation Assembly is for proofing use and is basically the same as Type I except for additional processing and signal conditioning circuitry. Type III Instrumentation Assembly is basically the same as Type I, except that Type III provides the means of monitoring either of two types of course gyroscope inputs.