This Mini Meter for high range iron measurements will give you direct readings in ppm.  Iron is naturally present in water supplies and its presence in both portable and industrial applications is regarded as objectionable.

Features & Specifications:

• Range: 0.00 to 5.00 ppm  (Fe)
• Resolution: 0.01 ppm
• Accuracy: +/- 0.04 ppm
• Deviation: +/- 0.01 ppm
• Method: EPA Phenantroline Method 315B
•  Light Source: LED 525 nm
• Battery: 1 x 1.5V AAA (included)
• Auto-off after 3 minutes of non-use and 2 minutes after reading