
PCA320 Free & Total Chlorine, pH and Temperature Analyser
Chlorine, pH, ORP and Temperature analysers
The PCA family are process analysers for the continuous measurement of chlorine and temperature. Also, pH (PCA320, PCA330, PCA340) and ORP where specified. The analysers feature built in data logging, RS 485 digital output, dosing relays, and alarm relays packaged in a wall mount Nema 4 x enclosure. The PCA340 also features two analog outputs.
The PCA300 family uses DPD Colorimetric method in which N, N-Diethyl-p-phenylenediamine indicator and a buffer are mixed together with the sample. The resulting chemical reaction causes a magenta colour to form in the presence of chlorine. The colour intensity is proportional to the concentration. The colour intensity is measured photometrically (light source at a specific wavelength and a photodetector) and converted to chlorine concentration, in mg/L, which is displayed on the front panel. The sampling interval for chlorine measurement is adjustable from 3 to 90 minutes.
Key features
- Backlit LCD Display
- Nema 4x protection
- DPD Chlorine measurement method
- Colorimeter diagnostics
- Reagent reminder
- Amplified pH/temperature probe
- Data logging of up to 3500 measurements
- GLP data for review of calibration information
- Digital RS485 output
- Two analog outputs for recording or dosing devices (PCA340)
- Two dosing relays
- SPDT alarm relay
- SPDT system error relay
- Warning messages
- Each PCA 300 series model is supplied with reagent bottles (2), reagent caps (2), 1 DPD compound powder, tubing and instructions

Frequently Asked Questions
Clear answers to help you choose the right water testing solution with confidence
Which brands of water testing kits do you supply?
Do you provide kits for both home and professional use?
Yes — whether you’re a pool or spa owner, aquarium keeper, utility company, or a university laboratory, we have the right solution for your needs.
Can I arrange servicing or calibration for my photometer?
Absolutely. We also provide servicing and calibration to keep your photometers accurate and reliable.
How quickly do you dispatch orders?
Orders placed before 2:30 pm (Monday–Friday) are dispatched the same day. We also ship on Saturdays for your convenience.
Which couriers do you use for delivery?
We deliver through UPS, DPD, and Royal Mail. You can also choose to upgrade to next-day delivery at checkout.
What is your return policy?
We accept returns within 14 days of delivery provided the items are unused, in their original packaging, and in resalable condition. Please contact our team before returning any items.
Can I place bulk or business orders?
Yes, we welcome bulk, trade, and institutional orders. For tailored pricing or large quantities, please get in touch with us directly.
How can I get help if I’m unsure which kit to buy?
You can call us at 📞 +44 (0)115888 2726 and our team will guide you in choosing the most suitable kit for your needs.
