The HORIBA LAQUAtwin ion-selective pocket meters measure a specific ion — nitrate, sodium, potassium, calcium or fluoride — directly in the field from a sample as small as 0.3 mL, or 0.05 mL using a sampling sheet. Each uses an ion-selective electrode (ISE) on HORIBA's patented flat sensor, so plant sap, a soil extract, or a drop of irrigation water can be measured on the spot instead of being bagged and sent to a lab.

For agronomy this changes the workflow entirely: nitrate or potassium results arrive in seconds while you are still standing in the field, so fertigation can be corrected the same day rather than the following week. All models are waterproof (IP67), calibrate at two points with the supplied standard solutions, run around 400 hours on two CR2032 batteries, weigh roughly 50 g, and take a user-replaceable sensor.

Choose your model

• LAQUAtwin NO3-11 (part no. 3200689162) — nitrate, 4 to 9900 ppm. General-purpose water and solution testing. Includes plastic case, syringe and 150 and 2000 ppm standards.
• LAQUAtwin NO3-11C (part no. 3200689163) — nitrate crop kit, 6 to 9900 ppm. Adds a carrying case, sap press and sampling equipment with 300 and 5000 ppm standards, for plant sap and petiole testing.
• LAQUAtwin NO3-11S (part no. 3200689164) — nitrate soil kit, 6 to 9900 ppm. Carrying case, press and sampling equipment with 30 and 300 ppm standards, matched to the lower concentrations found in soil extracts.
• LAQUAtwin K-11 (part no. 3200689160) — potassium, 4 to 9900 ppm. Includes plastic case, syringe and 150 and 2000 ppm standards.
• LAQUAtwin Na-11 (part no. 3200689159) — sodium, 2 to 9900 ppm. Includes plastic case, syringe and 150 and 2000 ppm standards.
• LAQUAtwin Ca-11 (part no. 3200689161) — calcium, 4 to 9900 ppm. Includes plastic case, syringe and 150 and 2000 ppm standards.
• LAQUAtwin F-11 (part no. 3200858466) — fluoride, 0.1 to 990 ppm. Includes plastic case, syringe and 1 and 10 ppm standards.

Which nitrate model?

All three nitrate meters use the same sensor; the difference is the kit and the calibration standards. Choose the plain NO3-11 for water and nutrient solutions. Choose NO3-11C if you are pressing sap from petioles and stems, where concentrations run high. Choose NO3-11S for soil extracts, which are far more dilute and need the lower 30 and 300 ppm standards to calibrate accurately.

Applications

• In-field nitrate and potassium testing of plant sap and petiole samples
• Soil nitrate and calcium testing from extracts, at the sample point
• Hydroponic and fertigation nutrient solution management
• Irrigation and well water quality assessment
• Nitrate monitoring in surface water, groundwater and agricultural runoff
• Drinking water fluoride level verification
• Sodium monitoring in boiler feedwater and process water
• Food and beverage QC on small samples
• Agronomy research, extension work and teaching laboratories

Documentation

• LAQUAtwin pocket meter brochure and specifications (PDF)
• LAQUAtwin ISE instruction manual, Ca-11 / K-11 / Na-11 / NO3-11 (PDF)
• LAQUAtwin nitrate meter instruction manual, NO3-11 / NO3-11C / NO3-11S (PDF)
• LAQUAtwin Ca-11 calcium meter instruction manual (PDF)
• LAQUAtwin Na-11 sodium meter instruction manual (PDF)

Parts & accessories

Replacement ISE sensors (S022 sodium, S030 potassium, S040 nitrate, S050 calcium, S060 fluoride), the matching standard solution sets, fluoride ion strength adjustor, sampling sheets and holders are all stocked — see the Horiba Parts & Accessories collection.

Browse all HORIBA instruments.