Volume Change Apparatus Manufacturer,Supplier and Exporter in India
Product Code : EL-CACTE-9462
Jlab Export is a leading Volume Change Apparatus Manufacturer,and suppliers in India
Hardened mortar and concrete change length as they dry, take up water or react inside. This apparatus casts a bar with reference pins in its ends. Its length change is then read on a comparator frame with a dial gauge reading 0.002 mm over 10 mm. A stainless steel reference bar with an insulated grip sets the zero.
Specifications
| Mould | One, with base plate |
| Reference pins | Four |
| Comparator | Length comparator frame |
| Reference bar | Stainless steel, with insulated grip |
| Dial gauge | 0.002 mm x 10 mm |
| Minimum order quantity | 1 unit |
| Dispatch time | Usually 7–10 working days |
| Manufacturer | JLab (Jain Laboratory Instruments Pvt Ltd), Ambala, India |
Shrinkage and Expansion Experiments
Students cast a mortar bar in the mould with the reference pins in place, so the pins set into the bar ends. After demoulding they zero the dial with the reference bar and take a first reading. The bar is stored under fixed conditions and read again at intervals. Keeping one bar in water and another in dry air shows swelling and drying shrinkage side by side.
Teachers can set this long-term movement beside a soundness test in the Le Chatelier Mould, which looks at early expansion of cement paste. Expansion of bars after steam curing is the basis of the Laboratory Cement Autoclave test, which also relies on comparator readings.
Frequently Asked Questions
How is length change worked out?
Subtract the first comparator reading from the later one and divide the difference by the effective gauge length of the bar. That gives the strain, often quoted as a percentage. A higher reading means the bar has grown, a lower one that it has shrunk.
Why does the reference bar have an insulated grip?
Steel grows slightly as it warms. The insulated grip keeps hand heat out of the bar. Its length then stays constant while the bar is used to set or check the zero of the dial gauge.
What does the dial gauge read?
It reads to 0.002 mm and has 10 mm of travel. That resolution suits the very small length changes that mortar and concrete bars show over the course of a test.
What are the reference pins for?
They are set into the ends of the bar as it is cast and give hard, fixed points to measure between. The comparator seats on the pins, so every reading is taken between the same two points.
Do readings need a steady temperature?
Yes. Take all readings in the same room conditions and let the bar and the comparator settle first. Otherwise thermal movement of the bar or frame is read as shrinkage or expansion.
Other Length Change Apparatus
- Length Comparator (dial gauge on a twin-pillar frame)
- Shrinkage Bar Mould
- Test Bar Moulds
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Last updated: 5 November 2026
