Gravity: Lab Grade Analog pH Sensor Kit (With Calibration Solutions)
📦 Location of the warehouse: China
Free Shipping from $50 in the US, $70 for non-continental US
- US Delivery Time: 2~7 Business days.
- Non-Continental US Delivery Time: 3~9 working days.
- Pre-Ordering: If an item is unavailable, you can pre-order it. We'll dispatch once stock is replenished, usually within 10 working days. Special pre-sale products will specify the expected arrival time in the description.
- Express Shipping: Need it faster? Contact us via email or through our live chat support, and we'll arrange expedited delivery for you.
Gravity: Lab Grade Analog pH Sensor Kit (With Calibration Solutions)
The Gravity: Lab Grade Analog pH Sensor Kit (SEN0161‑V2) is a high‑precision pH sensor designed for liquid analysis, accurately measuring acidity and alkalinity. Widely used in aquaponics, aquaculture, environmental monitoring, and water quality testing, this sensor provides reliable data for both hobbyists and professionals.
Compared to V1, the upgraded SEN0161‑V2 delivers improved accuracy and a smoother user experience. Its onboard voltage regulator supports a wide input range of 3.3V to 5.5V, ensuring compatibility with Arduino and other 3.3V/5V microcontrollers. The hardware‑filtered output signal minimizes noise and ensures stable, low‑jitter readings. With the included Arduino library, users benefit from two‑point calibration and automatic detection of standard buffer solutions (pH 4.0 and pH 7.0), making setup simple, reliable, and efficient.
This makes the Gravity SEN0161‑V2 pH Sensor Kit the ideal choice for IoT water quality monitoring, smart farming, and scientific research applications.
Projects
Project 1. Calibrating an Analog pH Sensor (with Linear Algebra)
Introduction: This video is an overview and tutorial for an analog pH sensor that's compatible with both Arduino and Raspberry Pi. It will also give a general overview of linear functions and interpolation. Plus it will show you how to write a custom code to use this sensor on an unsupported platform (Espruino).
Project 2. How to use DFRobot pH Meter module with an ESP32
Project 3. How to measure and indicate the pH of liquids with Arduino and LCD
Introduction: This video will show how to measure the pH of common liquids in our home in an easy and comfortable way perfect for monitoring the pH of fish, chemicals, etc.
Project 4. pH Sensor: Assembling, Coding, & Calibrating with Arduino | Smart Gardening
Introduction: This video talks about what pH sensors are, why use them for aquaponics system, and how to assemble, code, and calibrate the Gravity: Analog pH Sensor (Version 2).
Project 5. How to use pH meter V2 in ESP32 with new calibration
Introduction: This tutorial will teach you how to program with esp32 and how to do calibration with arduino IDE, how to use ph meter v2 in esp32 with new calibration.
Features
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Wide voltage input (3.3~5.5V), compatible with both 3.3V and 5V boards
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Low-jitter output signal thanks to hardware filtering
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Gravity interface and BNC connector for easy, plug-and-play setup
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Two-point calibration via software library with auto buffer recognition
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Uniform sensor size and connector for easier system integration
Applications
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Aquaponics and hydroponics systems
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Aquaculture water quality monitoring
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Laboratory chemical testing
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Environmental water sampling
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DIY multi-parameter water testing kits
Technical Specifications
Signal Conversion Board (Transmitter V2)
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Supply Voltage: 3.3~5.5V
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Output Voltage: 0~3.0V
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Probe Connector: BNC
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Signal Connector: PH2.0-3P
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Measurement Accuracy: ±0.1 @ 25℃
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Board Dimensions: 42mm × 32mm (1.66 × 1.26 in)
pH Probe (Lab Grade)
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Detection Range: 0 ~ 14 pH
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Zero Point: 7 ± 0.5
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Temperature Range: 5 ~ 60°C
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Response Time: < 2 minutes
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Internal Resistance: < 250MΩ
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Probe Life: > 0.5 years (depends on usage)
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Cable Length: 100cm
Package Contents
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1x Lab Grade pH Probe
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1x pH Signal Conversion Board (Transmitter V2)
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1x Gravity Analog Sensor Cable
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2x pH Standard Buffer Solution 4.0
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2x pH Standard Buffer Solution 7.0
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2x Waterproof Gasket
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1x Screw Cap for BNC Connector
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4x M3 × 10 Nylon Pillar
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8x M3 × 5 Screws
Important Notes
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Keep the BNC connector and signal board dry and clean to avoid measurement errors.
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Avoid placing the board on wet surfaces; use nylon pillars for mounting.
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The glass bulb at the probe tip is delicate — handle with care to prevent damage.
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Do not leave the probe connected to the board without power for long periods.
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Crystals forming around the protective cap are normal and do not affect accuracy. Return them to the cap if possible.
FAQ
How often does the pH probe need to be calibrated?
The calibration interval depends on the frequency of use. In general, calibration can be performed once a month. For frequent usage, it is recommended to calibrate the probe once a week. Always use fresh standard buffer solution during calibration to ensure accuracy.
Is two‑point calibration necessary, or can I perform only one‑point calibration?
For low‑demand applications, a single‑point calibration using a neutral buffer solution (pH 7.0) can be performed to confirm the zero point of the probe. In this case, the slope is assumed to be the theoretical value. However, to verify the actual slope, calibration with a pH 4.0 buffer solution should follow. Therefore, to achieve higher measurement accuracy, two‑point calibration is strongly recommended.
1. General Shipping Information
- We provide premium shipping methods with a tracking number for each order.
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Shipping address should be input in English without any special symbols to help the courier company recognize your address in the system. We will ship according to the shipping address you provided. Please notify us of any address change before your order is marked "Shipped" to avoid parcel loss.
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Please contact our customer service staff immediately if you need to cancel or change an order. Once your order has reached "Shipped" status, it can no longer be canceled or changed in any way. To avoid complications, please recheck your shopping cart before checkout.
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We can ship all in-stock orders within 1 business day as your order has been confirmed.
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All items are inspected before dispatch and are carefully hand-packed.
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With standard courier practice, you need to check the contents of the parcel before signing for your goods. Otherwise, we will not be held responsible for any damage that may have occurred in transit.
2. Shipping Options & Rates (United States)
(For Products in the US Warehouse & Global Warehouse)
2.1 Continental U.S. (50 States)
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| USPS Ground Advantage | $0.00 - $5.00 | $9.99 | 3-7 Business Days |
| USPS Ground Advantage | $5.00 - $50.00 | $5.99 | 3-7 Business Days |
| USPS Ground Advantage | Over $50.00 | Free | 3-7 Business Days |
|
USPS Priority Mail (Faster Option) |
$0.00 - $50.00 | $19.99 | 1-4 Business Days |
| USPS Priority Mail | Over $50.00 | $17.59 | 1-4 Business Days |
2.2 Non-Continental U.S.
(Includes Alaska, Hawaii, Puerto Rico, Guam, Virgin Islands, etc.)
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| USPS Ground Advantage | $0.00 - $5.00 | $9.99 | 5-9 Business Days |
| USPS Ground Advantage | $5.00 - $70.00 | $7.99 | 5-9 Business Days |
| USPS Ground Advantage | Over $70.00 | Free | 5-9 Business Days |
Important Notice:
- Before placing your order, please check the inventory location on the product page to confirm the delivery timeframes.
- For products stored in the Global Warehouse (Shenzhen), we will ship them directly from China.
- If you place an order for products from both the U.S. warehouse and the Global warehouse, we will ship your order separately: the products from the Global warehouse will be sent from China, and the products from the U.S. warehouse will be sent from the U.S. warehouse.
3. Warehouse Locations
Our products are stored in both our U.S. and Global warehouses to provide more flexible logistics solutions. On each product's description page, we indicate the specific warehouse location.
3.1 U.S. Warehouse
For products stored here, we use USPS for shipping. Logistics within U.S. are very efficient, with an estimated delivery time of 3-7 business days.
3.2 Global Warehouse (China)
Located in Shenzhen, Guangdong.
For orders shipping from our Global Warehouse, we typically use YunExpress. Given the complexities of international shipping, the estimated delivery time is around 10 business days, though this may vary due to customs processes.
4. Customs and Taxes
Effective Date: December 10, 2025
At OpenELAB, we are committed to providing accurate product descriptions and high-quality electronics. The following policy outlines your rights and obligations, designed to be fair to both our customers and our business operations globally.
1. Warranty Policy
A. Standard Limited Warranty (Global & US)
For customers in the United States, Asia, and other non-EU regions:
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Warranty Period: OpenELAB provides a 12-month warranty from the date of delivery.
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Coverage: This warranty covers defects in material and workmanship under normal use.
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Resolution: We will repair or replace defective units at no charge.
B. Statutory Rights for EU/UK Customers (EU Compliance)
If you are a consumer residing in the European Union or the UK purchasing from our global site:
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Statutory Guarantee: You are entitled to a 24-month statutory guarantee for conformity defects present at the time of delivery, in accordance with EU consumer protection laws.
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Relation: The Standard Limited Warranty (Section 1.A) applies in addition to, and does not replace, your statutory rights.
C. Warranty Exclusions (Applies to ALL Regions)
Warranty coverage is VOID if the damage is caused by:
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Misuse: Incorrect installation, reverse polarity, or exceeding voltage limits.
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Unauthorized Modification: This explicitly includes soldering, cutting pins, modifying the PCB, or flashing unauthorized/beta firmware that "bricks" the device.
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Physical Damage: Drops, moisture/water damage, or electrical surges (lightning).
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Normal Wear & Tear: Consumable parts (e.g., batteries), unless defective upon arrival.
Note: For non-warranty repairs (e.g., customer-induced damage), we may offer repair services for a fee. Shipping and diagnostic costs will be borne by the customer.
2. Return & Refund Policy
A. Return Window
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Standard: You may request a return within 31 days of receiving your order.
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EU Customers: You have the statutory right to withdraw from the contract within 14 days of receipt without giving a reason.
B. Refund Conditions & Restocking Fees
To protect against policy abuse, the refund amount is strictly determined by the condition of the returned item.
1. Full Refund (100%)
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The item is Brand New, Unopened, and Unused.
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The original packaging is intact and sealed.
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All accessories are present.
2. Partial Refund (Restocking Fee / Value Depreciation)
If the item is returned in a condition that prevents it from being sold as new, OpenELAB reserves the right to deduct a Restocking Fee (or "Compensation for Loss of Value" for EU customers) from the refund.
Deductions apply if:
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Signs of Use: Visible scratches, mounting marks on screw holes, or fingerprints.
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Damaged Packaging: Original box is torn, written on, or missing.
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Technical Modification: The device has been powered on, programmed/flashed, or soldered.
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Broken Seals: Anti-static bags or security seals have been opened.
Depending on the severity of the usage/damage, the deduction may range from 15% to 50% of the product price. Items damaged beyond repair due to misuse will not be refunded.
C. Shipping Costs
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Defective / Wrong Item: OpenELAB covers the return shipping cost.
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Customer Remorse (Changed Mind / Ordered Wrong Item): The customer is responsible for all return shipping costs to our designated return center (located in the US, Germany, or China, depending on your region). Original shipping fees are non-refundable unless required by local law.
3. Return Process (RMA)
To ensure a smooth return process, please follow these steps:
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Authorization: Contact us at info@openelab.io before returning any item. Returns without prior authorization will not be accepted.
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RMA Number: We will provide you with a Return Merchandise Authorization (RMA) number and the correct return address.
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Packing: Ship the item back in its original packaging with the RMA number clearly marked on the shipping label (not on the product box).
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Tracking: We strongly recommend using a trackable shipping method. OpenELAB is not responsible for returns lost in transit.
