The Marine Salinity Tester HI98319 from Hanna Instruments is a pocket-sized digital meter that reports the salt content of natural and artificial seawater in just a few seconds. Dip the graphite probe, wait for the stability indicator, and read salinity and temperature directly from the multi-level LCD. There are no optics to line up and no swing-arm to squint at, so every user in your team gets the same answer.

Marine Salinity Tester HI98319 digital meter displaying seawater salinity in ppt

Why choose the HI98319 Marine Salinity Tester

Refractometers and floating hydrometers drift with temperature and depend on how carefully you read a printed scale. This digital marine salinity tester instead measures electrical conductivity (EC) and converts it to salinity using the International Oceanographic Tables, so the result is objective, repeatable and easy to log. Readings can be shown in parts per thousand (ppt), Practical Salinity Units (PSU) or specific gravity (S.G.), which means the meter fits whatever unit your protocol, hatchery record sheet or reef-keeping guide already uses.

Three measurement scales in one instrument

0.0 to 70.0 ppt (g/L), resolution 0.1 ppt, accuracy ±1 ppt up to 40.0 ppt
0.0 to 70.0 PSU, resolution 0.1 PSU, accuracy ±1 PSU up to 40.0 PSU
1.000 to 1.041 specific gravity, resolution 0.001, accuracy ±0.001

Automatic temperature compensation

Conductivity changes sharply with temperature, so an exposed temperature sensor sits beside the electrodes and compensates automatically from 5 to 50 °C. A sample drawn from a cool sump and one taken from a warm display tank can therefore be compared with confidence, even during sudden temperature swings. Temperature accuracy is ±0.5 °C.

Graphite electrodes that will not oxidise

Stainless steel pins polarise and corrode over time, and that quietly pushes readings off target. The graphite sensors fitted to this meter resist polarisation and oxidation, so calibration holds far longer and long-term accuracy stays dependable.

Built for real working conditions

The HI98319 has a fully waterproof housing that is sealed against dust and water intrusion from any direction, so knocks, splashes and the occasional drop into a sump are not a problem. A protective sleeve is supplied to keep the sensor safe between tests. At 160 x 40 x 17 mm it slips into a shirt pocket or tackle bag, making it a genuinely portable marine salinity tester for field work as well as bench work.

Two-button operation and a clear display

Dual-button operation keeps the workflow short: power on, measure, read. The multi-level LCD shows salinity and temperature together and stays legible from an angle, while an on-screen stability indicator tells you the moment the reading has settled. A selectable auto-off function saves power if the meter is left switched on.

Up to 100 hours of battery life

A single CR2032 3V lithium coin cell delivers roughly 100 hours of continuous use. The battery icon blinks when replacement is due, so you are never caught out mid-measurement.

Where this marine salinity tester is used

Reef and marine aquariums, plus retail aquarium shops mixing synthetic seawater
Aquaculture farms, shrimp ponds and fish hatcheries
Seawater intake monitoring for desalination and reverse osmosis plants
Coastal and environmental water quality surveys
Saltwater swimming pools and salt chlorination systems
Food processing brines and laboratory sample checks

Fast single-point calibration

Calibration is automatic and takes one point at 35.00 ppt, matching average ocean salinity. Two single-use 35.00 ppt sachets and two 5.00 ppt sachets are included, and because each sachet is individually sealed you always calibrate with fresh, uncontaminated standard. Rinse the probe in the sample before measuring and the tester is ready again in moments.

Technical specifications

SKU	HI98319
Salinity range	0.0 to 70.0 ppt (g/L) \| 0.0 to 70.0 PSU \| 1.000 to 1.041 S.G.
Resolution	0.1 ppt \| 0.1 PSU \| 0.001 S.G.
Accuracy	±1 ppt (0.0 to 40.0 ppt), ±2 ppt above 40.0 ppt, ±0.001 S.G.
Calibration	Automatic, single point at 35.00 ppt
Temperature compensation	Automatic, 5 to 50.0 °C
Temperature accuracy	±0.5 °C / ±1 °F
Battery	CR2032 3V Li-ion, approx. 100 hours continuous use
Operating environment	0 to 50 °C (32 to 122 °F), RH max 100%
Dimensions	160 x 40 x 17 mm (6.3 x 1.6 x 0.7 in)
Warranty	1 year

What is in the box

HI98319 meter with CR2032 battery already fitted
Storage and protection sleeve
35.00 ppt calibration standard sachets (2 pcs)
5.00 ppt calibration standard sachets (2 pcs)
Instruction manual and quality certificate

Frequently asked questions

What salinity should a reef aquarium be kept at?

Most reef systems are held between 33 and 36 ppt, which is roughly 1.024 to 1.026 specific gravity. The Marine Salinity Tester resolves to 0.1 ppt, so small drifts caused by evaporation are easy to spot before corals are stressed.

How often should the meter be calibrated?

For hobby use, once a month is usually enough. For hatcheries, laboratories and commercial systems, calibrate weekly or before each critical batch of measurements using the supplied 35.00 ppt standard.

Can it measure freshwater or brackish water?

The instrument is optimised for seawater and brackish samples across the 0 to 70 ppt band. It is not intended for very low ionic strength freshwater, where a dedicated low-range EC or TDS meter is the better choice.

Is this marine salinity tester waterproof?

Yes. The casing is sealed against dust and water ingress from any direction, so brief immersion and wet-hand use are perfectly safe.

Buy the Marine Salinity Tester in Oman

Water Filter Oman supplies genuine Hanna Instruments testing equipment with local support and fast delivery across Muscat, Sohar, Salalah and the rest of the Sultanate. Browse the rest of our water testing meters and instruments, or contact our team for bulk pricing for aquaculture and desalination projects. Full manufacturer documentation for this model is published on the Hanna Instruments HI98319 page.

digital salinity tester

Marine Salinity Tester HI98319 – Hanna Digital Seawater Salinity Meter