EPA 180.1–compliant turbidity measurement with GLP data logging for audit-ready water quality records.
Apera TN500 (AI483) is a field-portable white light turbidimeter built on a tungsten filament lamp and 90° nephelometric scattering — the optical method required by U.S. EPA Method 180.1. Designed for commercial water quality programs where documented, defensible results matter: source water screening, RO/fertigation input verification, or compliance reporting.
The Apera TN500 is a portable, handheld turbidimeter that uses a tungsten filament lamp (400–600 nm) as its light source and the 90° scattering method specified by U.S. EPA Method 180.1. That optical configuration makes it the correct instrument class for regulated turbidity measurement in drinking water, groundwater, surface water, saline water, and domestic or industrial wastewater — and it is the same methodology required for compliance reporting in many state and federal programs.
Three auto-switching measurement sub-ranges cover 0.01–19.99 NTU, 20.0–99.9 NTU, and 100–1000 NTU. The meter resolves to 0.01 NTU at the low end, making it particularly well-suited for clean-water applications where slight cloudiness carries outsized consequence — municipal source water checks, RO permeate verification, or pre-irrigation quality gates in a closed-loop fertigation system.
Commercial cannabis and hemp cultivation facilities running recirculating hydroponics or coco-based fertigation systems rely on consistent input water quality to maintain predictable nutrient uptake and prevent biofilm or particulate fouling in drip emitters, valves, and sensors. Turbidity is a leading indicator: a spike in NTU before water enters the system is far cheaper to address than a clogged irrigation line or contaminated reservoir mid-run.
The TN500 is also the right tool for operations subject to state environmental or discharge permits, where turbidity readings on source or effluent water need to be logged, timestamped, and traceable. The GLP data store captures readings with real-time clock stamps and calibration history — the kind of chain-of-custody record that satisfies a third-party auditor or state inspector without manual transcription.
TruRead™ Multi-Reading Mode automatically captures multiple consecutive measurements and calculates average, minimum, and maximum values, then displays them as a brief report. On settling or variable samples — common in reservoir or pond water — this mode eliminates the single-reading variance that makes turbidity testing unreliable.
Zero-point calibration with a built-in error reminder is a critical reliability feature for low-turbidity work. The instrument flags when the 0 NTU baseline drifts outside tolerance, so operators know immediately if a recalibration is needed before recording a result. Calibration uses five AMCO high-molecular polymer standards (0, 20, 100, 400, 800 NTU) — EPA-approved, NIST-traceable, non-toxic, and stable for one year after opening. The tungsten lamp is user-replaceable, extending instrument service life without returning the unit for service.
The IP67-rated housing seals against dust and water immersion, and the 3.7V rechargeable lithium battery delivers up to 20 hours of continuous runtime — recharging via USB from a wall adapter or laptop. A large TFT color display with on-screen navigation supports English, Spanish, and Chinese. Data management runs through included PC-Link software (Windows); 200 stored reading sets with timestamps and calibration history export over USB.
In a purpose-built or retrofitted commercial grow, the TN500 earns its place at a few specific checkpoints: incoming municipal or well water before the RO skid, RO permeate before entering the nutrient mixing tank, and recirculating drain-to-waste effluent for discharge compliance or recycling decisions. Each of those checkpoints benefits from a meter that is both portable — so one unit can travel between rooms or buildings — and documentable, so readings are tied to a timestamp and calibration event rather than a handwritten notebook entry.
Because it ships as a complete kit — meter, all five calibration standards, sample vials, silicone oil, microfiber cloth, USB cable, and PC-Link software — the TN500 is operational the day it arrives with no additional consumables needed for initial setup. Contact Hydro Supply Co. to request a quote or discuss whether the TN500 or another Apera turbidity model fits your specific monitoring protocol.
| Model | Apera TN500 (SKU: AI483) |
| Measurement Method | 90° nephelometric scattering, tungsten filament lamp (400–600 nm) — U.S. EPA Method 180.1 compliant |
| Measuring Range | 0–1000 NTU (FNU), auto-switching: 0.01–19.99 / 20.0–99.9 / 100–1000 NTU |
| Calibration Points | 5-point: 0, 20, 100, 400, 800 NTU (AMCO polymer standards, EPA-approved, NIST-traceable) |
| Measurement Mode | TruRead™ (multi-reading: auto average, min, max) |
| Data Logger | 200 data sets with real-time clock, calibration history; USB export to PC (Windows) via PC-Link software |
| Display | Large TFT color screen with on-screen navigation; English / Spanish / Chinese |
| Battery | Rechargeable 3.7V lithium-ion; up to 20 hours continuous use; charges via USB |
| IP Rating | IP67 (dust-tight, waterproof to 1 m submersion) |
| Warranty | 2-year limited warranty (instrument) — Apera Instruments, LLC |
EPA Method 180.1 specifies the use of a tungsten filament lamp and 90° scattered-light detection for turbidity measurement in regulated water applications. The TN500 uses exactly that optical configuration (tungsten lamp, 400–600 nm, 90° scattering) and is explicitly designed to comply with EPA 180.1 for drinking water, groundwater, surface water, saline water, and domestic and industrial wastewater analysis.
The kit includes five AMCO high-molecular polymer turbidity standards at 0, 20, 100, 400, and 800 NTU. These are EPA-approved primary standards — non-toxic, NIST-traceable, and safe for standard disposal. They have a one-year guaranteed shelf life and are inherently stable (they do not settle from suspension under normal storage).
TruRead™ mode tells the meter to take multiple consecutive readings automatically, then calculate and display the average, minimum, and maximum — along with a brief data report for each session. Use it any time your sample may be variable or slightly settling, such as pond, reservoir, or runoff water. It eliminates single-point measurement error that would otherwise skew a recorded result.
The TN500 stores up to 200 measurement sets, each tagged with a real-time clock timestamp and associated calibration data. Records export to a Windows PC via USB using the included PC-Link software. The resulting data set provides a GLP-compliant chain of custody: who measured, when, against what calibration, and what result was recorded — without manual re-entry.
Yes. The IP67-rated housing is sealed against dust and incidental water contact, and the rechargeable battery supports up to 20 hours of continuous operation on a single charge. The meter is designed for demanding fieldwork alongside laboratory use, making it practical to move between fertigation rooms, reservoirs, and utility areas without concern about the instrument environment.
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