Reliable water analysis starts with readings you can trust on site, in the lab or directly in production. The GMH 5530 / 5550 family measures pH, ORP, rH and temperature for aquaculture, drinking water monitoring, sewage treatment plants, agriculture, food production, quality control and laboratory applications.
Users get precise handheld measurement with a resolution down to 0.001 pH or 0.1 mV and pH accuracy of ±0.005 pH. Automatic temperature compensation supports pH measurement when a Pt1000 or NTC 10K temperature probe is connected, while 1-, 2- or 3-point calibration with automatic buffer recognition helps keep measurements traceable and repeatable.
Built for demanding field use, the impact-resistant ABS housing is waterproof to IP65 / IP67 and even floats. The large dual display with backlighting improves readability in changing light conditions. For documentation-focused tasks, GLP functions, calibration interval reminders and, on the GMH 5550, calibration memory, analog output and data logger functions support structured measurement workflows.
The device measures pH and ORP potentials using suitable electrodes connected via the BNC socket. ORP values can be displayed as mV or converted to mVH according to DIN38404.
Pt1000 or NTC 10K temperature probes connect via two 4 mm banana sockets. With a probe connected, the device provides automatic temperature compensation for pH, rH and mVH modes and displays media temperature.
The device supports 1-, 2- or 3-point pH calibration with GREISINGER standard buffers, PHL buffers, DIN 19266 buffers or manual buffer input. The pH electrode condition is checked during calibration.
Two 4 1/2 digit 7-segment displays show the main measured value and temperature. Backlighting duration is adjustable, and a pop-up clip allows table-top use, belt attachment or suspension.
A 4-pole bayonet connection provides serial interface and supply functions with the USB 5100 accessory. On the GMH 5550, the same connection also supports a freely scalable 0 to 1 V analog output.
The GMH 5550 includes a data logger with measuring point input, adjustable recording interval from 1 s to 1 h, cyclic memory for 10,000 data records and manual memory for 1,000 data records.
