Apera Instruments 5051 Salinity Pen Tester – Pocket-Size Water Quality Meter

Apera Instruments 5051 Compact Salinity Pen Tester

The Apera 5051 is a pocket-size salinity pen tester built for fast, reliable salinity checks in the field, lab, or at home. Part of the Eco Series, it features a dedicated fixed salinity sensor optimized for rapid stabilization and accurate readings — no complex setup, no multi-parameter confusion. Slim enough to slip into a shirt pocket, the 5051 is the go-to tool for routine salinity monitoring across pools, aquariums, irrigation, and general water quality applications.

Why Choose the Apera 5051?

Dedicated Salinity Sensor — fixed, parameter-specific probe delivers fast stabilization and accurate readings without cross-parameter interference
Ultra-Compact & Lightweight — approx. 0.5 lbs; fits in any pocket or field kit for true on-the-go testing
Simple Point-and-Read Operation — no complex menus; instant salinity verification for everyday users and field technicians
Cost-Effective — professional-grade accuracy at an economical price point; no lab instrument required
Easy Maintenance — rinse and store at room temperature (15–25°C); minimal upkeep required

Ideal Applications

Swimming pools and spas: salinity monitoring for salt-chlorine generators
Freshwater and saltwater aquariums: routine salinity checks
Irrigation and agriculture: soil water salinity screening
Environmental field monitoring: general water quality verification
Food and beverage: basic brine and salinity checks

Eco Series Model Comparison

Model	Parameter	Best For
5021	Conductivity (EC)	General water conductivity & hydroponics
5031	TDS	Drinking water, RO systems, purity checks
5041	ORP	Pools, spas, disinfection monitoring
5051	Salinity	General salinity monitoring
5052	Saltwater Salinity	Saltwater aquariums & marine testing
5053	NaCl Salinity	Sodium chloride concentration checks

Technical Specifications

Parameter	Specification
Measured Parameter	Salinity
Sensor Type	Fixed, dedicated salinity sensor
Format	Single Unit (1-EA)
Storage Conditions	15–25°C (room temperature)
Weight	Approx. 0.5 lbs
Series	Eco Series Compact Pen Testers