The new pocket photometers MW-10 and MW-11 are a good solution for a quick and reliable measurement on chlorine. They display a direct reading, easiest than a colour comparison of test tubes. They are at a better cost than any handheld photometer.
They are dedicated for a quick control of water quality in swimming pools, aquaria, drinkable water plants, hydroponics, etc...
Both instruments work according to DPD requirements, DPD1 for free chlorine (MW10) and DPD4 for total chlorine (MW11).

Instrument: Direct reading photometer
Standard: Close to 330.5 USEPA Method (DPD reagents)
Principle: Receiver; Emitter LED, wavelength 525 nm
Resolution: ± 0.05 ppm Chlorine at 25°C
Test tubes: Ø 18.7 mm (glass)
Operating temperature: +1...+50°C
Humidity: 85 % RH, non condensing
Power supply: 1 battery 1.5 V AAA (auto switch-off after 2 min)
Dimensions – Mass: 87.5 x 63.7 x 35.2 mm – 65 g