Dräger C-7540 Dissolved Oxygen Comparator (0–40 ppb)

Overview

The Dräger C-7540 is a compact dissolved oxygen comparator designed for ultra-trace DO (0–40 ppb) in high-purity waters. Paired with CHEMets® ampoules (kit K-7540) using Rhodazine D™ chemistry, it delivers fast, repeatable ppb readings without a benchtop photometer—ideal for boiler feedwater, condensate, deaerator outlets, ultrapure/process water, and nitrogen-blanketed tanks where oxygen control prevents corrosion and efficiency loss.

Key Features & Specifications

• Measurement range: 0–40 ppb O₂ (visual color-match scale)

• Method: CHEMets® colorimetric, Rhodazine D™ for trace oxygen sensitivity

• Readout: direct ppb via stable comparator color blocks—no power required

• Use cases: power plants, refining/petrochem, desalination make-up, W/WW labs, aquaculture QA

• Form factor: rugged, lightweight, glare-resistant scale for field work

• Deliverable: comparator only; CHEMets ampoules/kits and accessories ordered separately

How It Works

A sealed CHEMets ampoule draws a fixed-volume sample and reacts with Rhodazine D to produce a pink/magenta color proportional to dissolved oxygen. Insert the developed ampoule into the C-7540 comparator, rotate to the closest color block, and read ppb O₂ directly. The sealed design minimizes air intrusion and handling error.

Applications

• Boiler/feedwater programs: verify scavenger dosing (sulfite/DEHA), target <10 ppb at economizer inlets

• Condensate & deaeration checks alongside online analyzers

• Process water/UPW loops in power, chemical, and pharma utilities

• Aquaculture & environmental spot checks where trace O₂ control matters

Operating Steps (Quick Guide)

1. Rinse clean glassware; avoid aeration (fill from bottom, overflow, cap immediately).

2. Snap the CHEMets ampoule per kit instructions; allow the specified development time.

3. Insert ampoule in the C-7540 and rotate to the closest color match.

4. Record the ppb O₂ reading, sample point, time, and operator initials.

Best Practices & QA

• Compare under consistent lighting; use a blank for colored/turbid samples.

• Keep sampling lines short; purge to remove stagnant water.

• Standardize daily checks (same glassware, timing, lighting) for trendable data.

• Store ampoules cool/dry; observe kit shelf-life and safety notes.

Compatibility & Ordering Notes

• C-7540 = comparator only (visual scale).

• Pair with CHEMets K-7540 (0–40 ppb); related ranges available per manufacturer.

• Optional: carry case, extra ampoules, sample vials, and SOP quick-card.

Why Seven Star LLC

We supply genuine Dräger/CHEMets solutions, provide SOPs tailored to boiler-chemistry programs, and help integrate handheld checks with your online analyzer strategy. Need multi-site kits, storage guidance, or training notes? We’ll package it for your team.

FAQ

Q: Can I use C-7540 for sub-10 ppb targets?

A: Yes—the 0–40 ppb scale and Rhodazine D chemistry are suitable for ultra-low DO when you follow best sampling practices.

Q: Does it need calibration or power?

A: No—reading is by visual color match against the fixed comparator scale.

Q: What’s included?

A: Comparator only; order CHEMets ampoules (e.g., K-7540) separately.

Call to Action

Request a quote—tell us your sample points (BFW, condensate, DA outlet), expected ppb range, and monthly test volume. We’ll ship the Dräger C-7540 comparator with the right CHEMets kits and a quick SOP card so your team can start same-day.