FANN Mud Balance Model 140
Technical Specifications
| Parameter | Value |
|---|---|
| Measuring Principle | Constant-volume balance beam |
| Density Range | 7 – 24 lb/gal • 45 – 180 lb/ft³ • 0.84 – 2.88 g/cm³ • 310 – 1250 lb/in² per 1000 ft |
| Resolution | 0.1 lb/gal • 0.5 lb/ft³ • 0.01 g/cm³ |
| Sample Cup | Anodized aluminum, vented lid, constant volume |
| Leveling System | Integrated bubble level and knife-edge |
| Construction | Chem-resistant beam, stainless fittings, lead-shot counterweight |
| Operating Temperature | Ambient (readings effectively temperature-independent) |
| Carry/Working Case | High-impact plastic with built-in fulcrum stand |
| Overall Weight | ~1.8 kg (4 lb) including case |
Model 140 Mud Balance — Four-Scale Drilling-Fluid Density Balance
The Fann Model 140 Mud Balance provides a fast, reliable way to measure the density (mud weight) of drilling, completion and work-over fluids. Its constant-volume cup and four graduated scales let field crews or laboratory staff read density in multiple units with ±0.1 lb/gal accuracy, ensuring proper hydrostatic pressure control and compliance with API 13B procedures. Because density readings are nearly temperature-independent, the Model 140 is the industry’s go-to mechanical balance for on-site mud checks.
Key Features of Mud Balance Model 140
Wide Density Range: Measures a broad range of fluid densities (typically 6.5–23 ppg or 0.8–2.9 g/cm³), suitable for various drilling fluids.
Direct Reading Scale: Calibrated scale provides immediate and accurate readings in multiple units (lb/gal, g/cm³, lb/ft³, kg/m³).
High Accuracy: Precision knife-edge balance with bubble level ensures readings are consistent and reliable.
Durable Construction: Made from corrosion-resistant materials (e.g., anodized aluminum or stainless steel), ideal for harsh field conditions.
Portable and Field-Ready : Compact and lightweight, often supplied with a protective carrying case for easy transport.
Simple Operation: No power or electronics required; mechanical operation allows use in remote locations.
Multi-Unit Graduations: Allows convenient measurement for various industry standards and international use.
| Feature | Benefit |
|---|---|
| Four integrated scales (lb/gal, specific gravity, lb/ft³, lb/in² per 1000 ft) | Immediate conversion between common oil-field units |
| Wide measuring range – 7 to 24 lb/gal (0.84 – 2.88 SG) | Covers light completion fluids up to heavyweight drilling muds |
| Temperature-stable design | Sample temperature has negligible effect on accuracy |
| Built-in bubble level & knife-edge fulcrum | Quick leveling and precise balancing on any rig floor |
| Rider weight with fine graduations | Readability to 0.1 lb/gal, 0.5 lb/ft³, 0.01 SG |
| Durable anodized beam & stainless cup | Resists corrosion from oil-based or salt-saturated fluids |
| Portable hard case with integral stand | Protects the balance and doubles as the base support |
Applications
Oil & Gas Drilling: Monitors mud weight to control formation pressure and prevent blowouts.
Geotechnical and Civil Engineering: Measures slurry or drilling fluid densities in soil investigations and borehole drilling.
Horizontal Directional Drilling (HDD): Maintains proper mud density for borehole support during underground utility installations.
Mining and Mineral Exploration: Used in exploration boreholes to manage drilling fluid consistency.
Environmental Drilling and Monitoring Wells: Ensures proper mud density to avoid borehole collapse and contamination.
Laboratory Testing of Fluids: Verifies properties of drilling or treatment fluids in controlled lab settings.
Drilling & Work-over Rigs – Daily mud-weight checks to control formation pressures
Mud Plants & Service Labs – Incoming product QA and blend verification
Cementing & Spacer Design – Quick density confirmation before pumping jobs
Geothermal & Mining Operations – Fluid density monitoring in harsh field conditions
Academic & Training Centers – Hands-on tool for teaching fluid-property measurem
Included Accessories
- Constant-volume balance cup with vented lid
- Four-scale balance arm with rider weight
- Knife-edge and bubble level assembly
- Base stand or protective plastic carrying case (with integral fulcrum)
- Lead-shot counterweight set (installed)
- Instruction manual & calibration guidelines
Pro Tips
- Calibrate with fresh water (8.34 lb/gal at 70 °F) each tour to verify accuracy.
- De-aerate foamy samples with a pressurized mud deaerator for best results.
- Keep the cup and lid clean and dry between tests to avoid scale buildup that can shift the rider setting.


