How Temperature Drift in Pressure Transmitters Causes Scrap

The Problem

Our extrusion line was producing variable sheet thickness, leading to frequent product quality failures. The melt pressure reading from the DR3418 4-20mA Pressure Sensor transmitter consistently showed a steady 250 bar, yet the scrap rate climbed to 12%. This discrepancy cost us approximately $35,000 annually in rework and material waste. We needed to identify the root cause quickly.

Root Cause Analysis

First, we suspected temperature-induced drift in the pressure sensor. Although the DR3418 is a high accuracy pressure transmitter, we observed that process temperature swings of up to 50°C caused the reading to shift by as much as 10 times the datasheet specification. Consequently, the uncompensated drift masked real pressure variations. In fact, the sensor’s output remained stable at 250 bar while actual melt pressure fluctuated between 240 and 260 bar. This means our quality control system was blind to the true process conditions.

The Solution

To resolve this, we replaced the existing transmitters with a temperature compensated pressure sensor model. Specifically, we installed the DR3418 High Accuracy Pressure Transmitter, which features integrated temperature compensation for stable readings across the operating range. Additionally, we recalibrated all units according to manufacturer guidelines. The new sensor’s 0.1% FS accuracy ensured that even small pressure changes were detected. Moreover, the stainless steel construction provided durability in our harsh industrial environment.

Results & Validation

Within two weeks, sheet thickness variance reduced by 60%. As a result, batch failures due to inconsistent melt pressure were eliminated. Furthermore, quality control metrics confirmed annual production cost savings exceeding $35,000, primarily from reduced rework and scrap. Indeed, the investment in a precision process transmitter paid for itself within months.

Key Specifications

• High accuracy measurement: 0.1% FS or better
• Temperature compensation for stable readings across operating range
• 4-20mA analog output with optional HART or RS485
• Wide pressure range selection for process applications
• Long-term stability and drift-free performance
• Stainless steel construction for industrial environments

Closing Question

Reflecting on this experience, how critical is it to choose a high accuracy pressure transmitter that can maintain accuracy under varying temperatures? For processes where product quality depends on precise pressure control, temperature compensation is not optional—it’s essential. Consider evaluating your current transmitters to ensure they meet the demands of your thermal environment.

Tags: #pressuretransmitter #industrialpressuresensor #4-20mAoutput #DR3418