Description
Strain gauge bridge amplifier SMM-DR for safety-related force and load measurement rated SIL3 and PL e category 3. The amplifier puts one bridge signal on two galvanically isolated current outputs, so that a safety controller can check the two channels against each other.
This is a safety component, not a measuring instrument: the redundancy comes from the two outputs, not from higher measuring accuracy. If the channels deviate by more than 10 %, the controller takes the plant to its safe state.
The test pulse input allows the measuring chain to be checked during operation: a 24 VDC pulse raises the current of channel B by 1 mA. The matching safety controller is the SCU-DR from the same range.
Features of the SMM-DR
✅Sensor input: 1 × strain gauge full bridge 350 Ω
✅Bridge sensitivity: up to 4 mV/V
✅Bridge supply: 5 VDC
✅Analog output: 2 × 4 … 20 mA, channel A and B, galvanically isolated
✅Nominal range: 8 … 16 mA within 4 … 20 mA
✅Load resistance: 500 Ω max.
✅Test pulse input: 24 VDC ±20 %, ≤ 250 Hz
✅Safety rating: SIL3 (EN 61508, EN 62061) · PL e category 3
✅Supply: 24 VDC ±10 %, 100 mA max.
✅Housing: DR22.5 for TS 35 rail · 117.2 × 22.5 × 113.6 mm
✅Protection: IP20
✅Temperature coefficient: < 50 ppm/K
✅Order number: 0600-00492