Specifications
uThing::iPH
Key Features¶
- Output Formats: JSON, CSV, or Human-Readable
- Host Compatibility: Linux, macOS, Windows, and Android systems (drivers integrated in most OS)
- Data Reporting Rate: Configurable from 1 second to 1 hour
- Galvanic Isolation:: Isolated power and data paths for to the analog domain and ADC
- Calibration: Guided 2-point calibration with automatic buffer detection
- Temperature Compensation: Automatic (ATC) using either the on-board sensor or an external probe
Technical Specifications¶
Measurement Performance¶
| Parameter | Range | Resolution | Stability (*1) |
|---|---|---|---|
| pH | 0 - 14.00 pH | 0.001 pH | 0.01 pH / 24h |
| ORP | ±1,650 mV | 0.1 mV | 1 mV / 24h |
| Temperature | -55 to +85 °C | 0.0625 °C | n/a |
Electrical Characteristics¶
| Parameter | Value | Notes |
|---|---|---|
| Input Impedance | > 1 TΩ (1x1012 Ω) | Ensures compatibility with high-resistance probes |
| Input Bias Current | 20 fA (typical) | Minimizes measurement error |
| ADC Resolution | 18-bit | Provides high-resolution voltage readings |
| Power Input | 5V DC via USB | |
| Power Consumption | 23 mA (115 mW) |
Physical & Environmental¶
| Parameter | Value |
|---|---|
| Operating Temperature | -40 to +85 °C |
| Operating Humidity | 10 to 90 %RH |
| Dimensions | 100.2 x 19.8 x 23.5 mm |
| Weight | 24.8 g |
Dimensions¶
uThing::iPH dimensions in mm
NOTE: Understanding Measurement Stability¶
(*1) The stated stability is for the measurement instrument itself. When measuring pH/ORP in real-world conditions, readings can drift over time due to several factors related to the probe and the environment:
-
Temperature Equilibration: It can take 10 to 20 minutes for the temperatures of the electrode and the solution to fully equilibrate. A changing temperature will cause the reading to drift until thermal stability is reached.
-
Probe Fouling: If the glass bulb is dirty or fouled, it will slow down the diffusion of ions from the solution to the sensing membrane. This results in a sluggish response to pH changes and can appear as a slow drift towards the final value.
-
Reference Junction Memory: When a probe is moved between samples, liquid from the previous sample can be temporarily trapped in the reference junction. As the new solution diffuses in and the old solution diffuses out, the junction potential changes, causing the pH reading to drift. This effect is most severe when the ionic composition of the two solutions is very different. The time required for this memory effect to dissipate can range from a few minutes in flowing junctions to over an hour in gel-filled probes.