iAttenuation vs DOT Chart 17
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iAttenuation
This app calculates resistor values for various passive attenuator networks. It supports T, Pi, H, O, and Minimum Loss Pad configurations, allowing users to input impedance and desired attenuation. It can also adjust resistor values to standard tolerances.
- Calculates resistor values for passive attenuator networks
- Supports Tee, Pi, H, O, and Minimum Loss Pad configurations
- Input and output impedance calculation
- Desired attenuation input
- Adjusts resistor values to standard tolerances (1%, 5%, 10%)
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Passive attenuators are two port / four terminal resistive networks that are designed to reduce (or attenuate, hence their name) the power between a source and load. They can also match the impedance between the source and load. They are used in a variety of audio and radio / RF applications. iAttenuation calculates resistor values for the following types of attenuator networks: Tee Network Pi Network H (Balanced Tee) O (Balanced Pi) Minimum Loss Pad Just enter in the input and output impedance values, and the desired attenuation, and iAttenuation does the rest! iAttenuation can also adjust the calculated resistor values to match the nearest standard 1%, 5%, or 10% tolerance values.
DOT Chart 17
Access a full-color display of hazardous materials markings, labels, and placards. This app provides quick visual information and regulatory citations for shippers and carriers. It serves as a general guidance tool for hazardous materials regulations.
- Full-color display of markings, labels, and placards
- Access to Hazardous Materials Regulations (HMR) citations
- Quick visual information for shippers and carriers
- Mobile access to DOT Chart-17
- Guidance on 49 CFR Parts 171-180
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The Pipeline and Hazardous Materials Safety Administration’s (PHMSA) DOT Chart-17 provides a full-color display of the markings, labels, and placards specified in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). This mobile application allows shippers, carriers, and other stakeholders to quickly access visual information and HMR citations from DOT Chart-17. Note that this application is intended for general guidance only and should not be used to determine compliance with 49 CFR, Parts 100-185.
Screenshots
Verdict
The clearest difference is price: DOT Chart 17 at Free against iAttenuation's $2.99. DOT Chart 17 also leads on update cadence (every 10 months vs every 69 months) and iOS requirement (11.0 vs 15.6). iAttenuation's advantage is rating (3.0 vs 2.3). On ratings volume, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
DOT Chart 17 is free to download; iAttenuation costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
iAttenuation holds the better App Store score, 3.0 against 2.3. Both are backed by a comparable volume of ratings — 2 and 3 respectively.
iAttenuation ships an update every 69 months, DOT Chart 17 every 10 months. The most recent releases landed on October 5, 2026 and October 10, 2026 respectively.
| Parameter | iAttenuation | DOT Chart 17 |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 3.0 (2 ratings) — better | 2.3 (3 ratings) |
| Positive reviews | — | 0.0% of reviews |
| Number of ratings | 2 | 3 — better |
| Update frequency | Every 69 months | Every 10 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 11.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 20 MB |
| Age rating | 4+ | 4+ |
| Developer | Black Cat Systems | Pipeline and Hazardous Materials Safety Administration |
Customer experience
iAttenuation
DOT Chart 17
In-app purchases
iAttenuation
No in-app purchases
DOT Chart 17
No in-app purchases
