GESTRA SPECTORconnect – Conductivity Electrodes for TDS Control
LRG 16-60, LRG 16-61, and LRG 17-60 are designed for continuous conductivity measurement in boiler water and TDS (Total Dissolved Solids) control in steam boilers and hot water systems. When paired with the LRR 1-60 controller, they provide continuous blowdown control. Integration with URS 60 / URS 61 enables use as conductivity limiters up to SIL 2 safety integrity level.
Measurement Principle
LRG 16-60 / 17-60 utilize a two-electrode conductivity measurement. The LRG 16-61 employs a four-electrode configuration, suitable for higher conductivity ranges. All models feature temperature compensation to 25°C via integrated Pt1000 sensor.
Technical Data
- Connection: G1 A, EN ISO 228-1
- LRG 16-60 / 16-61: PN40, 32 bar(g) at 238°C
- LRG 17-60: PN63, 60 bar(g) at 275°C
- Measuring range LRG 16-60 / 17-60: 0.5–6000 μS/cm
- Measuring range LRG 16-61: 50–10,000 μS/cm
- Lengths: 180/200 up to 1000 mm, depending on type
- Power supply: 24 VDC ±20%
- Communication: CANopen / CAN bus ISO 11898
- Protection: IP65
Blowdown Control
The LRR 1-60 controller processes CAN telegrams from the electrode and actuates a modulating blowdown valve using PI 3-point stepping control. Features include MAX/MIN alarms, 4–20 mA process value output, and standby input for external valve closure command.
Installation
Minimum distance from boiler wall, flue tubes, and internal metal parts: approx. 30 mm for LRG 16-60 / 17-60 and 60 mm for LRG 16-61. Electrodes and measuring tubes must not be cut. Use shielded twisted-pair CAN cable for wiring.
Maintenance
Inspection includes checking for deposits on the measuring tip, verifying temperature compensation, seal integrity, CAN bus errors, and functional testing of the blowdown valve.