Hioki SM-8216, Instruction Manual, Page: 21 / 44

9
3. OPEARATING PRINCIPLE
The SM-8216 super megohmmeters consist of a constant voltage power
supply and a high sensitive current measuring section to be combined to
compose a resistance measuring circuit.
The current measuring section is composed of a current detective resistor,
And low drift voltage amplifier.
A measured resistance value is on a large analog meter.
Fig. 3.1.1 shows a circuit composition of the SM-8216.
Fig. 3.1.1 SM-8216 Circuit Block Diagram
Meter
Indicating
Voltage
Converter
Current‑to‑
Proportional
Resistance
Control Circuit
High Voltage
Power Supply
High Voltage
Circuit
Discharge
Selector
Function
Black
Measuring Rod(+)
Measuring Rod(‑)
Red
Measure
Sample to
VOLTAGE Selector
Alarm
1/R
Optional Signal Outouts
DC Amplifier
ＤＩＳＣＨＡＲＧＥ
ＣＨＡＲＧＥ
ＭＥＡＳＵＲＥ
ＨＶ−ＥＮ