The HI735 Total Hardness Checker® (Low Range) is a compact, high-accuracy digital water hardness meter designed for fast and reliable measurement of total hardness from 0 to 350 ppm (mg/L) as CaCO₃. Manufactured by Hanna Instruments (Romania), this handheld checker replaces subjective visual test kits with precise digital results you can trust.

Using an EPA-recommended colorimetric method, the HI735 measures calcium and magnesium hardness via a red-violet reaction. It displays results instantly on a clear LCD—ideal for laboratory, industrial, environmental, and water treatment applications.

Key Features & Benefits

• Low-Range Total Hardness Measurement
  Measures 0–350 ppm (mg/L) as CaCO₃, perfect for potable water and process monitoring.
• High Resolution & Accuracy
  • Resolution: 1 ppm (mg/L)
  • Accuracy: ±6 ppm ±6% of reading @ 25°C
• Reliable Colorimetric Method
  Based on EPA Method 130.1, ensuring standardized, repeatable results.
• Advanced Optical System
  • Light source: LED @ 470 nm
  • Detector: Silicon photocell
• One-Button Operation
  Simple workflow minimizes training time and operator error.
• Portable & Battery Powered
  Compact, lightweight design with auto-off after 10 minutes to conserve battery power.

Typical Applications

The HI735 Total Hardness Checker is widely used for:

• Drinking water quality testing
• Water treatment plants & RO systems
• Environmental monitoring
• Industrial process water
• Aquaculture & aquariums
• Laboratories, schools, and field testing

Technical Specifications

• Range: 0 to 350 ppm (mg/L) as CaCO₃
• Resolution: 1 ppm (mg/L)
• Accuracy: ±6 ppm ±6% of reading @ 25°C
• Method: EPA Method 130.1 (colorimetric)
• Light Source: LED @ 470 nm
• Detector: Silicon photocell
• Operating Environment: 0 to 50°C; max 95% RH (non-condensing)
• Battery: 1 × 1.5V AAA alkaline
• Auto-Off: After 10 minutes of non-use
• Dimensions: 86 × 61 × 37.5 mm
• Weight: 64 g

What’s Included (Starter Kit)

• HI735 Total Hardness Checker®
• Total Hardness Low Range reagents (2 tests)
• Sample cuvettes with caps (2)
• 1 mL graduated syringe with tip (2)
• Plastic refilling pipette (1)
• 1.5V AAA alkaline battery (1)
• Instruction manual

Why Buy from Labzobd.com

• Authorized supplier of genuine analytical instruments
• Quality-checked products with proper documentation
• Competitive pricing for laboratories, utilities, and distributors
• Secure packaging and reliable delivery
• Professional pre- and post-sales technical support

The HI735 Total Hardness Checker® delivers laboratory-grade accuracy in a handheld format—making it a dependable, cost-effective solution for precise total hardness testing anywhere, anytime.